Talk:Nether portal/Archive 1

Preparations
Everyone is showing preparing for these portals with traps, waterfalls, and airlocks. I don't recall reading anything that said the Ghasts could come through the portals. If they can, is there a way to temporarily turn off a portal to prevent this, or does this break the link to the Slip? Even if it does, why not just recreate it later, it should connect to the same spot?

In addition, people have these airlock rooms, but on The Slip page it says Ghasts create an impact crater with their attack. Doesn't this suggest they can eventually chew their way through a wall? I just don't want to waste a lot of time and resources building a "portal room" just to find out it's useless. Thoughts? MrMatthew 12:27, 29 October 2010 (CDT)


 * Notch said (on Twitter) that Ghasts could spawn near portals if the room was big enough. Ghasts probably COULD destroy the walls, but they won't attack unless they see you. So an airlock would be the best since you could cut the room off and dig to the ceiling and drop lava or something. You can turn a portal off with an explosion or by destroying the Obsidian. PurpleKiwi! 20:08, 1 November 2010 (UTC)


 * ok ok, i can't stand this. im gonna say it once. GHASTS CAN ONLY SPAWN IN THE NETHER!!! nothing can go through the portal except for you!! Nothing will spawn out of it.


 * I'm going to say this once. you have no proof. end of. go ask notch for official information, like I did with herobrine.--Kizzycocoa 16:34, 1 November 2010 (CDT)


 * here's some proof for you, it's rare but ghasts and pigmen *can* spawn in the normal world.. http://www.youtube.com/watch?v=1cDgCPDKq5o&feature=player_detailpage#t=821s Wrincewind 16:11, 10 May 2011 (UTC)


 * the only reason for pigmen spawning on the normal world is when a pig is struck by lightning and i dont think ghasts can spawn anywhere else but the nether anyway.-- HamMaster4 10:20, 9 October 2011

Video Links
That second video looks really sketchy, not to mention it's short and doesn't explain anything. I'd recommend taking it down. The other link is great! MrMatthew 19:15, 27 October 2010 (UTC)

I found a better video to replace the first one :) --PANDA EXPRESS 17:18, 27 October 2010 (CDT)

Since this is really old I didn't want to change anything,but I notice there's no other video of how to make a portal.I made short video explaining with an alternattive way.Here: http://www.youtube.com/watch?v=wfe0D0vlh-8 .if is suitable please post it.Thanks.SniperCharlie 23:09, 5 April 2011 (UTC)


 * Do you really need a video on how to build a frame? – ultradude25 ( T at 00:23, 6 April 2011 (UTC)

Is really obvious for the ones who are playing the game from long time but new players are starting everyday and not everyone plays multiplayer.Since this is the wiki where all is explained I thought could be useful.And is a good method to build anything out obsidian.So,do what you want with it.At least some are finding useful:)SniperCharlie 01:25, 6 April 2011 (UTC)

Block Icons
Is there any way someone can bring over the block icons used on the forums? The portal diagram used in the first post here is a much better way to describe it. --PANDA EXPRESS 07:50, 27 October 2010 (UTC)

-- I've added it, but I'm not sure if it's legal like this --Gemberkoekje 08:00, 27 October 2010 (UTC)

That looks awesome! I added an arrow between the two (replacing the "becomes" text) let me know if you like the text better and I'll replace it. --PANDA EXPRESS 17:18, 27 October 2010 (CDT)
 * Changed the diagram to fit in with other templates within the wiki. --Antome 09:30, 1 November 2010 (UTC)

Should we change the name?
Should this article's name be changed to "Slipgate"/"Slip Gate"? --TelephoneKiosk 19:33, 29 October 2010 (UTC)

Placeable purple portal blocks?
Is there a dec code for portal blocks? Being able to place portals wherever would be awesome (Griefing by filling someone's house with portals?!)
 * The decimal value is 90. (not hard to find considering the other Halloween blocks had similar values) Have fun! --Antome 12:39, 31 October 2010 (UTC)
 * There is one major problem with this idea, as soon as a portal block updates, unless it is part of a portal it will be destroyed.--74.227.250.179 20:40, 1 October 2011 (UTC)

Portal icon
Changed the address of the portal comparison to fit with the icon. Either I or someone else will need to do a better render later :3 --Antome 13:11, 31 October 2010 (UTC)
 * Created a far better render :D --Antome 05:35, 1 November 2010 (UTC)

Portal Size?
Does the obsidian have to be 4x5? The article implies that that's the case, but the portal on the left in the screenshot (http://www.minecraftwiki.net/images/f/fa/Portalcomparison.png) appears to be 3x5. Charles Stover 08:40, 31 October 2010 (CDT)
 * that's a squished image. it's still 4x5.--Kizzycocoa 13:42, 31 October 2010 (UTC)
 * Thanks. That's what I was thinking may have been the case. Charles Stover 13:43, 31 October 2010 (UTC)
 * We reallllly need to update that image...Kenji 03 13:02, 5 November 2010 (UTC)
 * What's squished about it? Aside from the bottom line being underground, how could you be confused by it? – ultradude25 ( T 13:06, 5 November 2010 (UTC)

Portals on the Ground
Is it possible to build a portal horizontally (on the ground) instead of vertically, so that you'd fall into it instead of walk into it? Charles Stover 13:42, 31 October 2010 (UTC)
 * nope. x/y axis only!--Kizzycocoa 13:45, 31 October 2010 (UTC)

Momentum
I don't know why it's important to have "Contrary to public belief, portals do not conserve momentum" in the article (Valve's Portal reference). Isn't that as irrelevant as something about how contrary to public belief, portals do not spawn demons (Doom reference)? Unless it really is public belief that portals conserve momentum, I feel like it's just a reference to another game (I'm biased. I played Portal). Also, how do we know the portals don't conserve momentum? You have to hold still in it to "teleport", and even if you did move, how do we know you didn't move the slight distance during the 20-30 second wait while the Nether loads?

--DaMavster 15:31, 1 November 2010 (UTC)
 * I was wondering that myself, really --Antome 05:02, 2 November 2010 (UTC)
 * I laughed when reading that, and my physics student room mate agrees with Valve that "a portal should (in theory) conserve momentum". It is kind of irrelevant here, but again: I found it funny.Kenji 03 13:01, 5 November 2010 (UTC)
 * it doesn't. in fact, it makes you stand in the centre of the portal once you've teleported.
 * besides, people want ground portals, and may be misguided by the fact you have to stay inside it. also, we all thought portals would be just walking into it. IMO, it's a good line, slightly funny, and helps to show how the portals won't work like in Portal, which many expected.--Kizzycocoa 13:04, 5 November 2010 (UTC)

Very Messy
This page needs to be cleaned up.
 * The wording sucks.
 * There are lots of spelling/grammar mistakes.
 * The Trivia section is almost as big as the article.
 * The article seems like it was written in chunks. It doesn't flow. (some places say "earth" and others say Earth)
 * Purplekiwi, if you have a problem with the flow of the article, why not change it yourself? Yes it is a big article, potentially unnecessarily big, However it is difficult to cut certain pieces of information as many have an edge of importance to them --Antome 00:00, 2 November 2010 (CDT)

Ghast-ly turn of events.
So I wish I would have possibly got a screen shot of the ghast spawning in my home but alas I was too worried about him burning down my house seeing as it is in it's entirety wood. Though the little bugger managed to burn down the majority of my home I had my revenge. Thought all the people that said that Ghasts only spawn in The Nether would want to hear about this. My word of advice, build your portal room out of stone.

And yes, I thought the title was clever.


 * I'm going to build a portal in the middle of the forest just for fun. :D --PurpleKiwi 05:52, 2 November 2010 (UTC)

Obsidian Harvesting?
Portals seem to be a way of harvesting obsidian. Since you can use 10 blocks of obsidian to create a second portal next to you old one, use it and collect the 14 blocks of obsidian the new built portal provides. Afterwards you can enter you old portal and use the one you build for havesting again and it will create another 14 block portal. not sure if it works didn't try it out yet.
 * It appears that if you deactivate the portal which appears through the glitch where you get a duplicate portal, another portal is created within close proximity to it. So yes, currently that would be a way to harvest obsidian. --Antome 06:35, 3 November 2010 (UTC)

Passage of Time
After finally setting up a functioning portal system between my two largest bases, I re-planted my tree farm on the smaller of the two. As I had forgotten some stone at the other base, I went though the portal and to the other base -- a trip that took less than thirty seconds. When I came back to the smaller base, nearly all of the trees were fully grown. By 'fully grown" I mean the huge trees that are well over 12 blocks high! I was astounded. Awestruck. Amazed.

What I'm getting at here is this: is it possible that time passes quickly on "Earth" when you're in the Nether? This could be a definite reason of why the watch goes crazy when in the Nether (not that it needs a reason -- you are in hell). el payaso 00:15, 3 November 2010 (EDT)


 * Forgot your sig there, pal. As to answer your question, possibly, though I'm not sure about it. The reason for the watch going crazy is actually not because of this quicker passage of time, if it exists, but rather because the Nether literally has no time. CyborgDragon 04:11, 3 November 2010 (UTC)

Natural Portals?
On my world I found 3 naturally occurring portals in a triangle shape. I was traveling and found them a good distance from my already made portal. When I enter them, they all go to the same one in The Slip, but when I exit they all return me to the same of the 3 portals on the Overworld. THe portal made in The Slip is also ridiculously close to the one I made, which is odd considering the distance the Overworld portals are from each other. I was wondering if this has happened to anyone else and if it is supposed to happen or is a glitch.Please post on here if it has or is!

These are pictures of the portals, both in and out of The Slip.

On the Overworld

In The Slip

Original Exit Portal and 3 found portals

4th portal

5th portal (relative to 4th portal)

Key:

Red - Portals I found, lead to blue in The Slip.

Blue - Portal I found that others I found exit from The Slip at and enter The Slip at.

Yellow - Portal That I originally came out of when I first exited The Slip.

Green - Original Portal I entered The Slip from, exits to yellow.

Later found a 4th portal, about 100 blocks from my original exit portal (portal that appeared when i first exited The Slip). It also brings me out of the portal circled in blue from above pictures.

--Cheezy8 18:28, 3 November 2010 (UTC)

I have now found a 5th portal, leads to same one in The Slip and exits at same one as others on the Overworld.

--Cheezy8 18:51, 3 November 2010 (CDT)


 * Actually, it's a bug. Look at this tweet. It was acknowledged by Notch himself. I've added the reasoning for this in the article some time ago. --Scykei 02:11, 4 November 2010 (UTC)


 * I have read about the portal glitch/farm. This is not the case for me. I only created 1 portal, ever. I then had 1 portal created for me(Marked in yellow in above pictures)from which I exited The Slip. I later found 3 (now 5) other portals at much farther distances from my original. I didn not create any others that would lead to the game creating any.The natural portals don't function as normal portals do either. All 5 of the portals exit from the same portal in The Slip (you go through any of them and come out at same one). In theory each one, or perhaps two(if they are connected[1 is entrance 1 is exit]) should have created a single Portal in The Slip, resulting in multiple new portals, not one.--Cheezy8 23:16, 4 November 2010 (UTC)


 * I am also experiencing random, inexplicable spawning of portals. I made one portal sort of deep in the mining tunnels of my spawn point's home hearing that they can spawn ghasts. I entered, exited, and ended up a comfortable ways from my home. I was relieved and continued playing. That was days ago in real life. Just now I climbed a mountain near to a new home and what do I see in the distance frighteningly near my old one? Yup, a portal. It has spawned without me doing anything that should spawn it; I only EVER used my original portal and the one that resulted from Minecraft moving me out from a wall/floor in the Nether.


 * These kinds of bugs always freak me out. For me it's like seeing a mundane object in your room, turning to focus on something else for a few seconds, looking back and noticing that it has obviously moved. And you're the only one in the house. In other words: I am still too scared to go anywhere near it. I'll post more when I get the courage. --Notthross 01:25, 7 November 2010 (CST)


 * After talking myself into going through the portal this morning, I discovered that it does send me to my original portal in the Nether. When I decided to leave (which was rather soon), I found myself back at my 'exit' portal. If this is a bug, and not just some tactic by Notch to try to freak us out (which worked), it may be that the game keeps trying to move you in the Nether.


 * To not confuse MYSELF, I'll go in chronological order: You create a portal and enter for the first time. The game sees that you would end up in a wall/floor/ceiling, and consequently moves you, thus creating a new portal on Earth (as we'll refer to it here), and effectively tying your portal in the Nether to two on Earth. You leave, wander around for some time, and re-enter through your original portal. However, you'd still be teleported into that same wall/floor/ceiling so the game tries to move you again, this time in a different direction. The problem is that portal on Earth is still tied to that first one in the Nether, so it sends you there, but it still created the new one on Earth where you would have gone, had you not already had that first one up.


 * This is just my theory based on what limited experience I've had with them, and assumes that the 'exit' portal on Earth is created when you're enterING the Nether (i.e. loading screen) and not when you're already there. What I could probably try is to destroy the first portal in the Nether, make a new one and go back, then try to go through my original portal on Earth and see if it reactivates the one in the Nether, or creates a completely new one in a different area. --Notthross 14:13, 7 November 2010 (CST)


 * Your theory makes sense and I believe this bug was fixed with a very small patch recently. Thank you for explaining the bug to me. --Cheezy8 21:22, 7 November 2010 (UTC)


 * I believe this may be relevant here; after creating a portal, I dug a fairly long stretch straight through the Nether (using hundreds of blocks of cobble to create bridges as need be), then placed another portal back on the other end. This took me out into a winter zone, well away from my original base (a grassy area). I decided to use Cartograph to see how much distance I'd actually travelled. This, however, showed two other chunks that had been generated between my entrance/exit points - with portals slap bang in the middle of them!


 * So I put all my gear in a crate, headed back down into the Nether, and went for a swim in the Lava. Upon my death, I noted the "building chunk" messages on my way back to the respawn point, and sure enough Cartograph showed another generated chunk + portal on my Earth map, relative to my last position in the Nether. - Bomb Bloke 08:13, 8 November 2010 (CST)


 * 09 November: I have definitely found a naturally occurring portal. What I originally did for my adventures in the Nether, I made a portal in, then made a second portal exactly 125 blocks away (so should be approx 1000 blocks away in the real world). I then came out the other end, and ran back home to see how long it would take. Took quite a few minutes, but that wasn't good enough.


 * Portal 1 (on Earth)


 * This portal is directly under my house, my spawn point is literally 10 or so squares straight forward and up. I'm facing East in this picture. Notice the Mossy Cobblestone corners, not obsidian. I don't make my portals with Obsidian corners (though exit portals will have them).


 * Portal 1 (in the Nether)


 * This is me standing in Portal 1 in the Nether. I'm facing east, if you look forward you can see the start of my torch trail. 125 blocks forward is Portal 2.


 * Portal 2 (in the Nether)


 * This is Portal 2, I'm facing east. You can see the separation of my torches, and to the left you can see my trail continuing. Notice the lack of corners.


 * Portal 2 (on Earth)


 * This is Portal 2 on Earth, I'm still facing east, sun is rising in front of us, spawn is behind us. Another oddity I wanted to point out as well is shown in this picture. Although the Portal 2 I made in the Nether faces East/West, this one came out facing North/South. Strange, no?


 * Well the next time around, I ran the same original 125 blocks through the nether, then just continued on, weaving around all the lakes of lava and walls, but continuing in the same general direction. As I ran, I placed torches every 5 squares or so . I'd gotten to about 180 torches in (x 5 = 900, x 8 = 7200 real world blocks) when I made my 3rd portal (The problem with this is the trail weaves around to make it past lava lakes and mountains in the way, but nevertheless, it's a pretty great distance), and again started off to make it home.


 * Example of the Trail


 * This picture just shows an example of my trail, unfortunately photo bucket made the pictures smaller than they are, so you can't see torches off in the distance.


 * Portal 3 (in the Nether)


 * This is Portal 3, I'm facing east still. Not a lot to say. Notice that it lacks corners again.


 * Portal 3 (on Earth)


 * Here's Portal 3 on Earth, I came out in a cave =\. I eventually found my way out by digging up (into some water, so that was good). I'm facing east in this picture again, my spawn is behind me to the west.


 * I ran a full days distance, got to a lake and was looking around, when I saw a portal off in the distance. I ran to it, thinking maybe it was my 2nd portal, but then as I got closer I realized it wasn't anything at all what I remembered around my 2nd. So I went in, and it plunked me in a cave in the nether. I started exploring, found my way out, and it didn't take long for me to find my Torch trail, I was about 4/5ths the way towards Portal 3 in the Nether.


 * Portal-Natural (on Earh)


 * Here is Portal-Natural on Earth. When I first found it, it had just turned day, this is the time it was when I went back to take a picture. Notice the Moon rising in the east, my spawn behind me in the west. Also, it has full obsidian corners.


 * Portal-Natural (in the Nether)


 * Here's where I came out of in the Nether. It has it's corners. I'm actually facing North in this picture, possibly another type of incident like what happened with Portal 2. I had to run through the cave and then dig a little to make it down to my trail.


 * Split Path


 * This is where I came out of the cavern that Portal-Natural spawned in and where the Torch Trail meet. I'd say this is about 4/5ths the distance towards Portal 3 in the Nether, but just an estimate.


 * So anyways, that's it right there. I tried exploring around Portal-Natural on Earth to see if I could find some other random one's like the stuff explained above this, but didn't find any. But I definitely found this one, so they're out there, it's just probably going to be very difficult to stumble across them. --Jk_Caron 14:50, 9 November 2010 (UTC)


 * Very interesting. Maybe you should cartograph your save and check around for any other oddities/portals? Sounds like your world could be a good one to try it on. --Fishrock123 19:09, 9 November 2010 (UTC)


 * I have never been to the nether in 2 of my worlds, but there are definitely portals on the map. While clearing out space for a station using a map editor it cut 2 of them in half. It was surrounded by rock too... In the other world one generated right next to my door, but I've never been to the nether there either... Nickguletskii 02:56, 14 November 2010 (CST)

Same here, I created a new world, and near to the respawn point, behind various trees(seems like a forest) there was a portal. Someone can use a map editor in a never played map to confirm it. "Natural" portals really do exists.--Ddragoonss 12:46, 17 November 2010 (UTC)
 * This has happened to me too, I just built a portal to the Nether and used it for some time. Then, when I was just randomly wandering quite close to the original portal, I discovered a new one! It was generated there all by itself in the middle of nowhere. So I go through it, and find myself in a new portal in the Nether just next to the one according to the original portal in the Overworld. When I go into the according original portal, I find myself in the new one in the Overworld! Later, I discovered, that regardless of which portal in the Nether I use, I have to face differently if I want to go to the original one, or the "natural" portal in the Overworld.--Danny Ufonek 18:38, 18 January 2011 (UTC)

One-way portal?
It seems whenever I make my very first portal, after going to the nether and back I end up at a different portal EVERY time! Making a second portal in the Nether will allow me to travel to and fro between that portal and it's partner, but I can never seem to get my first portal to take me back and forth. Anyone else have this problem? Kenji 03 13:00, 5 November 2010 (UTC)
 * Yeah it's a bug that should be fixed now. – ultradude25 ( T 08:01, 5 November 2010 (CDT)
 * The bug isn't fixed. I have Beta 1.2_01 and I still get out at a different portal. .nNa., 23 January 2011

Proximity Testing
I did a bit of testing with portals and found some interesting things about the space between portals. First, so far, it appears that elevation changes in both worlds at the same time. Climbing down a mountain in the Nether will put you underground in the real world. This led to me setting up a portal to see if it would end up in a wall. It didn't. Conclusion: Portals need space in both worlds to be created, so you will never appear inside a wall or in a lake of lava.

Second, I set up a portal on the surface of the real world and went through it, walked one block, and set up another portal. When I went through the new portal, I ended up in the first portal I ever set up--about 30 blocks underground. When I went back to the surface to investigate, there was only one portal. Conclusion: Within a certain distance in either world, blocks traveled in one world will not correspond with blocks traveled in the other.

Hope this information helps. Pyroclasticman 20:41, 5 November 2010 (UTC)

Problems with more than the 14 block frame
Because one of my portals opened up to a 50 block drop into the middle of a Nether Magmaflow, I decided to block up one side of the portal with more obsidian blocks. The portal continued to work fine until it was unactivated by a Ghast. Afterwards, I was unable to reignite the portal with my flint and steel. Removing the 6 blocks from the back of the portal frame allowed me to reignite the portal. Also -- my Nether is a place of explosion-pocked blocks and fire. I *hate* Ghasts. GazerOrion 23:08, 5 November 2010 (CDT)

New World
I built a portal, travelled to the Nether, built another portal about 50 blocks away and turned right angles. The second portal in the Nether sent me to a new, normal world. The old world was normal, the new world was snowy. I built towers to above the clouds in both worlds and I could not seen the other tower. In the new world, there was a mob spawner. The game was set on peaceful.Andrewn 03:39, 21 November 2010 (CST)
 * Odd... What does a map display tool like minutor show of your map/s? '''[[User:Aclectasis| A ]] CLECTASIS ''' 04:45, 21 November 2010 (CST)
 * Peaceful mode doesnt hinder mob spawners from existing. They just wont spawn any hostile mobs (Actually they do but the mobs are removed immediately so you dont notice). As for the snowy: you landed in a tundra or taiga biome (Biomes DO work on savegames before the Halloween Update, you just have to travel to new chunks to see any). If your towers are 50 blocks away from each other in the nether, theyre 800 blocks away from each other in the overworld. Try making a structure at the spawn point (of your old world) if there isnt already, and find your way back to it from the "new" world with a compass. --BlueLegion 06:52, 21 November 2010 (CST)
 * "If your towers are 50 blocks away from each other in the nether, theyre 800 blocks away from each other in the overworld."

He will actually be 400 blocks away in the Overworld. Nether compression is 8x, not 16x as originally announced in the update.

Portal matching and coordinates
Some messing around with the F3 debug key has proven a simple mathematic relationship between portal locations -- and how to "fix" your portals so that they work two-way. Basically, a portal in the overworld at coordinates (Xo, Yo, Zo) will "prefer" to transport you to the Nether at (Xo/8, Yo, Zo/8) -- note that the Y coordinate (up/down) is not scaled. However, with the current implementation if these ideal coordinates are obstructed in some way then it will search around quite a distance and either link you to the closest existing portal or create a new one in the "wrong" place. (Note that since the coordinate system is compressed in the Nether, it is far more likely that it will locate a nearby existing portal when building portals to the Nether than for ones returning from the Nether.) Removing the obstruction and rebuilding the portal in the correct location will fix things. Also note that existing portals can be moved vertically (Y coordinate) any distance without affecting linking; you can quite happily use a portal at the very top of your Nether to link to bedrock in the overworld, or vice versa. Only the X/Z positions matter. Using these rules means that you can set up a very safe Nether transit system very easily -- unless you enjoy dodging the Ghasts all the time. --Miral 03:18, 5 December 2010 (UTC)
 * So, I've found out something kinda weird. I have 1 portal in the Nether, and if I'm standing on one side of it (or farther to one side) I port back to the expected portal in the real world. If I'm in the other direction (same portal in the nether) I get ported to a new portal in the real world. Anyone else experience this? --JonTheMon 04:54, 5 December 2010 (UTC)
 * Your analysis of portal creation is slightly incorrect.

"However, with the current implementation if these ideal coordinates are obstructed in some way then it will search around quite a distance and  either link you to the closest existing portal or create a new one in  the "wrong" place"

It actually searches for an existing portal to link to before using the ideal coordinates. Then builds a different one if the ideal coordinates are blocked.

And Jon, that likely means that, on one side of the portal, it is finding the correct portal to link to within the search range and linking to it. But from the other side, that portal isn't in range, and needs to create a new one.

Hey, I just found a weird portal that I didn't make way off from where my main one is. If I go through it, I come out in the nether at the portal that I normally use, and if I go back into the portal I come out at the one I built myself. Why is this other weird portal way out there as a one-way trip? LB 00:49, 1 February 2011 (UTC)

Bad portal spawn location
I built a portal with corners and then walked through it and... i was hundreds of blocks above an insanely huge magmaflow. I've tried moving the portal and reigniting it at the same spots but nothing helps. How can i fix this?


 * I can think of two things that might help. First, you could remove everything from your inventory, go to the Nether, break one of the non-corner blocks of the Portal frame with your fist (it takes a while but it can be done), and kill yourself. When you reactivate the frame in the Overworld, it will probably create a new Portal frame in the Nether, but the location may be as bad or worse. Second option, you could create a Portal frame in a more ideal location in the Nether and then permanently disable your old frame. Problem with that is the new Portal will almost certainly create itself a new Portal frame in the Overworld instead of using your first Portal's frame as an exit. The mechanics behind Portal auto-creation and entrance-exit connections are still ambiguous and unpredictable, so there's no sure-fire solution.
 * ISmartMan 17:37, 31 January 2011 (UTC)

Boats
With Invedit, I tried going through a portal (one purple block) in a boat, and the same thing that happens to minecarts happened to me (stuck in the portal screen). Just thought I might point this out. Also, I was playing around in the nether, put down a portal and the other one spawned in the middle of a zombie dungeon. I don't know if the dungeon part is relevant or not, but it's interesting...

Portal Link Fixing
About this line in the article: "In the event of two portals (Portal 1 and Portal 2) on Earth linking to the same portal (Portal A) in The Nether, it will be necessary to build a second portal (Portal B) in The Nether."

I didn't want to just jump in and edit the article (because I'm so new here) but I have found that it's not necessary to build a second portal. Instead it's possible to enter The Nether (by entering Portal 1 or 2), disable the portal in The Nether (e.g. a Ghast shot or TNT), return to the normal world by dying (or another, separate portal I suppose), and then enter The Nether from Portal 2 (the one you think shouldn't link to portal A). This has (at least once) caused a new portal to be created in The Nether, closer to the place I expected it to be.

Trivia Too big?
I don't know if it's just me, but does it seem to others that the Trivia on this page has grown fairly uncontrollably? I think we should limit it down to something more reasonable, many of the bits are interesting but do we need so many? Perhaps more of them can be written into the article. -St. Fenix (User•Talk) 17:19, 16 January 2011 (UTC)

Broken Portal
I am not sure why but when i built my portal it didnt work. I thought i was being clever when i built it by making obsidian in the shape of a portal because i dont have diamond (old world died and was deleted somehow) And i was wondering if anyone else had a similar problem or fixes?

Natural appearing portal - mapped
In my new world, I built a portal, and I'm normally using it. But somehow, just when I mapped out my world (pictured) there appeared a new one! I haven't visited it yet, nor have I built another portal in the Nether. This has happened in my previous world too, and it's quite freakking mee out. --Danny Ufonek 18:00, 20 January 2011 (UTC)


 * Is this a question? What am I missing?  This happens often with portal duplication. Dctrjons 06:59, 21 January 2011 (UTC)


 * Don't feel super freaked out the same thing happened to me this morning. I was exploring on peaceful in this HUGE cavern when i see light at the end of a tunnel. When i went to investigate, I found that it was a portal. It took me to my regular portal spot in the Nether and returned me to my home-portal on return. Maybe a form of fast-travel? Khosumet 05:25, 8 February 2011 (UTC)

A mistake in the trivia: Using portals while on fire
"If you use a portal while you are on fire, when you teleport to your destination the fire will be extinguished."

The above statement is false. I caught myself on fire in the Nether, used the portal, and when I arrived back in the surface world, I was still on fire. I can confirm this time and time again as of update 1.2_02 LB 00:32, 1 February 2011 (UTC)

You are still on fire, but the "fire effect" it's not displayed. It also happens for potions particles. 123Qwerty 09:12, 15 June 2012 (UTC)

Error in Trivia Section: Not Being able to place Portals next to each other.
Yeah... as proven by a variety of images here, this is untrue.

I think that the people on that thread misinterpreted the wiki page. Their portals didn't have the portal blocks touching each other, just the obsidian. I tested it, and if you try to have two portals with one directly in front of the other, the first one goes out as the second one is lit. Meaning... Two portals cannot be layered. Pitzik4 03:42, 8 February 2012 (UTC)

superportals
yeah, i just made a huge, as I'm calling it, "superportal". The frame is 8 blocks high and 6 blocks wide, with 24 portal blocks inside. it seems to be able to teleport to at least 7 places. I think it would be worth noting in this article about the possibility of making one, even if making one most of the time may need a third party program. proof of it is right here http://www.youtube.com/watch?v=Yg2boV7Gnrc Darkbeing 21:02, 14 February 2011 (UTC)

Portal Sounds
Has there been any mention of the distance Portals emit sounds being too far away? They seem to emit that sound tremendously far away. Simpsons Rule 18:32, 1 March 2011 (UTC)Simpsons Rule

Portals on server
The article states that portals don't work on servers- it's worth mentioning that with Bukkit's multiworld support, this is possible.

Diagram?
Where's the diagram in the article? It just says "this diagram" but there's no diagram.JesusChrist666 03:29, 5 March 2011 (UTC)

image/portal size
can we put the image of the portal back up? or at least write somewhere on the page the size it needs to be? Gil212 07:46, 8 March 2011 (UTC)

Better description
Well if we can't call the portal a ring, why not have a better picture? I spend 30mins going by the current picture trying to make a portal in frustration and I realise now from reading this discussion page that the lower part of the Obsidian is below the ground! :-)

It needs to be clearer IMHO.

--Quatermass 16:34, 13 March 2011 (UTC)

Natural portals Question
Do they really exist? and where can they be found? Only in the real world or can they be found in the nether as well? Because I have generated a map of 200 mgb, mostly searching for a natural portal, and still haven't found one.
 * It is/was a glitch where when creating a portal and a duplicate spawned in the nether, another would occur on the overworld. Even under an extreme set of circumstances where, say, lava was formed in a portal shape and was exposed to water naturally, there is no way to light it. Darkid 18:06, 25 March 2011 (UTC)

So if there are no netural portals, maybe that part should be cleared from the text about portals?

On 1.9 pre-release3, on 10th October 2011, a couple of hours after Notch twitted that he had deployed a surprise, I created a new world and I was spawned near a NPC village that had a portal. I used the seed -1379608828. I deleted that world and created it again but it was different. I don't know if the "surprise" deploy was that. Unfortunaterly, I'm afraid I can't replicate that. Maybe someone else can, though. ChakAttack 13:08, 10 October 2011 (UTC)

multiplayer
can somebody please add a section about whether or not it works in multiplayer--Ash0011 00:39, 5 April 2011 (UTC)

as of 1.6.6 the nether was opened in smp even though the portals could be made and lit since they first put out portal. Killrbladez 17:03, 6 November 2011 (UTC)

Mobs going through portals
In the trivia, it states that mobs cannot go through portals, which makes them good doors. I have not tested with other mobs, but a slime just followed me through portal blocks. If the intention was that mobs cannot use portals to go into or out of the nether, then the meaning isn't clear.

Skeletons can go through portals, too.

Wording is fixed now. Thanks!

I figured out why Portals seem to show up in the Normal world
When you DIE in the Neather the game creates a portal for that location on the other side, i discovered this few weeks ago because im using a mapping program. i kept noticing random generated chunks that didn't connect to my normal area far away. at the center of each square was a portal. so i did some testing... made a new world. used INVedit to make a portal. traveled really far died on purpose. mapped it and there was a random square landmass with a portal in the center miles away not connected to my starting area. i traveled to it and used it... it took me to the general spot where i died in the neather... I would really like it if people could confirm this--Silverfox6000 13:06, 25 April 2011 (UTC)


 * I think that this may have been added in a recent update, because it is definitely true (I was trying to figure out why out of nowhere I was getting a natural pair of Portals) and that had never happened to me before. I die pretty often in the nether, but only go every no-and-then (I go with just a sword to fight Zombie Pigmen when I'm bored). Can anyone else go test this out and confirm it? It seems to be true for me. --DwarfWoot 03:23, 27 April 2011 (UTC)

Notch i love you! you fixed this! Thank you Thank you Thank you Thank you Thank you Thank you!--Silverfox6000 00:31, 27 May 2011 (UTC)

Multiplayer portals
Is there any mod for multiplayer servers which would allow connecting two Portals in Overworld, since there is no Nether in multiplayer so far? --TakeruDavis 21:48, 27 April 2011 (UTC)
 * It probably depends on what kind of server you are running, but yes, there are tons. Bukkit has a number of Nether plugins, though from what I've seen, none of them offer a perfect simulation of SSP Nether (ex: skybox is usually the same as a normal world, which looks really goofy in the daytime, portal generation is different, etc) (edit: These are all to simulate having the Nether though, not sure about two overworld portals connecting, but probably) --Warlock 21:59, 27 April 2011 (UTC)
 * I didnt mean simulating Nether, I meant connecting two in Overworld. But since now there IS Nether, it would be better to bond two portals, but no matter if they are same world or different. --TakeruDavis 17:07, 26 May 2011 (UTC)

Ghasts/ Zombie Pigmen come out of portals
I'm pretty sure that Ghasts and Zombie Pigmen come out of portals now as is evident in this video: Did Notch secretly release this update or is it just a glitch that happened.
 * The video shows no proof of this - the player may have simply spawned them off camera.

yeah its the same on my world 2 my house was destroyed by a ghast the i got slaughterd by pig men.

Maximum distance for linked portals
In attempting to create an alternate mode of travel from my mineshaft to my sky island, I created two portals, with the expectation that once 1.6 hit, I'd be able to create a safe track between the two in the Nether. Turned out, they both linked to the same portal in the Nether. This isn't exactly a problem, since which portal I come out of in the normal world seems to be either random, or based on some arcane formula involving my position within the portal and my facing--so with a little luck and a lot of retrying, I can end up where I want by re-entering the same portal in the Nether.

On an experiment, though, I decided to go 200 blocks in the negative X direction (north) and create another portal, to see if maybe it would create a Nether portal 25 blocks away. Instead, it linked it back to the same portal--and this one seems one-way; the Nether portal will still only take me to the first two portals that linked to it, seemingly at random.

So can anybody with more spare obsidian than I answer the question: How far away does a portal have to be in the real world from any other linked portal, in order to spawn a new portal in the Nether instead of linking to an existing one? Moreover, is it possible to de-link a portal in the Nether and re-link a new portal in a separate location? (As in, extinguish the Nether-side portal as shown above, walk 25 squares north, create a new portal, light up both portals and have the first one link to the first two portals and the second one link to the 200-blocks-away one?) Alfador 03:45, 27 May 2011 (UTC)


 * I have similar problem. My gate... sorry, portal is on x 221;y 53;z -3 (P-1) (since height is not considered as I have read, I emphasize remaining two coords) and my friends portal on 195; 91; 39 (P-2). Lot of time I tried enter my portal, but using spawned portal only sent me to his portal instead of mine. Now, we have Not-crossing-each-others-borders policy, which this portal problem violated. I reentered Nether many times, only to break Nether side of portal. Few times new portal spawned 1 block near old one and in total, it switched 3 different location. But actually I got lucky with one location afterall. Only one which was almost enclosed cave, with lavapool to light the area. This time it spawned portal and it lead back to mine portal, not the friends. It was cave I appeared with portal in few times before. It was on Nether coords 43;41;14(P-A), while previous attempts spawned portals around 30;39;14(P-B). This 13 blocks on x coord made the difference.
 * However, I expected friend would experience same problem, appearing in nether portal (P-A) created by me and being ported into my base(P-1), using this portal to get back, so I rebuilt portal on said previous coords (P-B). This allowed both of us safe way to their respective homes, but at same time messed a bit with way to Nether. My portal (P-1) again leads to old coords - port (P-B), actually both of Overworld do lead there.
 * To sum it, P-B is both portals receiver and sends to P-2, while P-A is only to send to P-1.
 * Since safe passage in both direction is granted and no risk of Ghasts or angry Zombie Pigmen is present, I believe we both could agree on this constelation, and I dont actually care that I end on his Nether-side portal, but still, if somebody could tell me, reason why I appear there, eventually suggest direction in which should I move Nether portals(I cant move friends OW portal and mine was built long time ago 1.6, being already incorporated in complicated structure), I would be GLaD.
 * One more sum of X-Z coords of portals
 * {| class="wikitable"

! Portal ! X ! Z
 * P-1
 * 221
 * -3
 * P-2
 * 195
 * 30
 * P-A
 * 43
 * 14
 * P-B
 * 30
 * 14
 * }
 * TakeruDavis 11:56, 27 May 2011 (UTC)
 * 30
 * 14
 * }
 * TakeruDavis 11:56, 27 May 2011 (UTC)

I'm interested in this question, too, as I'd like to set up pairs of portals next to each other and create a teleportation chain. Here's one data point: in our world, one portal in the overworld links to a nether portal that is a solid 60 meters away in nether coordinates. This corresponds to 480 meters away in the overworld, so that's a minimum. Knowing the maximum distance would be good for efficiency, though not critical: basically, you should be able to look at any two portals in the overworld (with 2 x maximum distance) and put two portals in the nether exactly between these two. One will link to each, then, if done right. Erich666 19:53, 27 May 2011 (UTC)

I have the answers for how this mechanic works, available here. I did a decompile of the 1.5_01 source code. Feel free to take whatever you want from it for this article. I'm not sure how to decently put that information here without taking up an entire page of its own. pudquick 04:31, 28 May 2011 (UTC)


 * Based on Pudquick's guide, I've been able to determine that the seemingly random behavior of my portal was in fact anything but. The one block of difference between the left and right side of the portal corresponds to an eight-block difference in the overworld... and that is enough to cause it to teleport to either of the two portals depending on which side one stands in. Much more convenient than I could have hoped for. I got lucky.
 * Anyway, the formula seems to be thus: 128/8 = 16, so portals within 16 squares of one another in the Nether SHOULD be able to link to the same portal in the overworld, assuming only one exists at the closest point to each portal's corresponding spot in the overworld (X*8, Z*8). 128*8 = 1024, so portals must be at least 1025 blocks apart in the overworld to guarantee that a NEW Nether portal will be generated rather than linking to an existing portal. Moreover, if a portal between 129-1024 blocks away from the original portal links to the Nether portal, it is a one-way trip--it cannot link back even if the original overworld portal is disabled. The only way to ensure that a portal 17-1024 blocks from another overworld portal links to a unique portal in the Nether is to BUILD that other portal at the proper location.
 * I apparently got INSANELY lucky in that I effectively built two portals at once by automatic generation, given that each side of my Nether portal links to each of the two portals I built specifically for that purpose. I now have four entrances to my floating island (minecart track, waterfall, central ladder pillar, and portal) and three to my main mineshaft (ladder, drop pool, portal). Alfador 10:00, 31 May 2011 (UTC)

Bug preventing activating of portals
While trying to make a portal in an obisdian-glowstone-temple, I stumbled upon a bug: If there is, at the bottom level of the opening (one block higher than the bottom of the frame), an obsidian block behind the opening, you can't spawn a portal by setting the frame block in front of it on fire (but you can on the other side). If you put 2 obsidian blocks behind the opening or one in front of it and one behind it in crisscross sequence, it's impossible to spawn the portal. Putting the blocks there when the portal is allready spawned makes no difference. Also, putting the obsidian blocks on any other height or taking, for example, dirt instead of obsidian will have no impact on the portal-spawning ability. My guess is that this is a security measure to prevent someone from putting two portals into each other. Klaue 19:44, 7 June 2011 (UTC)

JavaScript portal calculator
I built a javascript portal calculator for my own server to simplify figuring out portal placement. It's here: http://pastebin.com/Df1bnXN7

I wasn't sure if javascript content was allowed on the wiki, but if it is and if someone wants to take a shot at cleaning it up and adding it, feel free... D3phoenix 00:35, 20 July 2011 (UTC)

Creation of sibling-portals by the system
When I build my first Nether-Portal it created a corresponding Portal in the Nether.
 * If I build a portal in the Nether, will a new corresponding portal be crated in the average world?
 * Same Question vice versa: If I build another portal in the average world, will an extra portal materialize inside the Nether?

--Yatsufusa 07:40, 27 July 2011 (UTC)

Can someone please repair this page?
It was edited to something that i don't understand, can someone edit it back? I've tried, but it doesn't allow me to change so mutch stuff.

If anyone can edit it, please restore the previous version before the edit.

Bakugo 08:31, 8 August 2011 (UTC)

Noticed something when making portals.
I got lost in the tunnels of The Nether while exploring it, so decided to portal out. I put a portal at Bedrock level in The Nether, and came out to my newly created portal. What I found odd was this portal had 18 blocks - both sides had 2 Obsidian making little platforms to stand... I'm not sure if that' mentioned in the article, although someone else must have noticed. Is any part of that noteworthy? No, right? MegaScience 18:31, 21 September 2011 (UTC)


 * it is already mentioned under part 4 of Linkage of Overworld and Nether. However, it is a little buried and sorta mentioned in Implications as well (last point), so there needs to be some changes, I'd think. --JonTheMon 18:43, 21 September 2011 (UTC)


 * Likely in the section about harvesting portals, since they mention 14 when it can be 18 if taking ones generated like that... MegaScience 18:48, 21 September 2011 (UTC)

Air Portal
Shouldn't it have a spot on this page, considering its "Portals"? --Throex 02:24, 7 October 2011 (UTC)


 * Nope. This is about Nether Portals. Once official names and such are put out, the other pages might be different and not fit even more... MegaScience 02:26, 7 October 2011 (UTC)
 * Then shouldn't it be renamed "Nether" Portal. Instead of just "Portal".. --Throex 03:04, 7 October 2011 (UTC)


 * Perhaps we should hold off until the air portal has an official tooltip name. After that it'd be best to move this and make a disambiguation. – ultradude25 ( T &#124; C ) at 04:27, 7 October 2011 (UTC)


 * You know....this is a portal specifically for traveling to and from the Nether. Just move it to Nether Portal and make this a summary/disambiguation page. Not much to discuss about this. Edit: sorry if I sounded mean...just saying something. - Asterick6 22:49, 8 October 2011 (UTC)


 * The page is called portals so it would make sense that we have a big page on portals instead of two pages on, just like the stairs or slab pages.--HamMaster4 10:30, 9 October 2011


 * Disambig page can be found here: Portal (disambiguation). I left a redlink for the creation of the Ender Portal when we get more info on it. --HexZyle 04:25, 9 October 2011 (UTC)

Item Duplication "Bug"
"If your enter in a Portal while you are crafting, items are dropped to the ground and the items become infinite. This is a duplication bug. However, the original item cannot be used or put into storage. But the original item can be destroyed."

It should be said that this only works on single player. I've tested this on multiplayer, and it does not work. There seem to be others who can confirm that this bug works only on single player. Search YouTube for a video titled "Minecraft Nether Portal Duplication Glitch (read desc.) [1.7.3]" by eldersscrollsFTW, and scroll down to the comments.

I tried adding an external link, but there seems to be no way to actually answer the bot-test question. There's no submit answer button, and I can only press Show Preview, which brings me back to where I was before. I do have cookies enabled in my browser, so no dice from the help page. 98.239.103.193 05:35, 25 October 2011 (UTC)

igniting porals
how do i ignite portals? I have tried but the only thing that happens is that i set th obsidian on fire.

try lighting the f---ing inside of the portal Killrbladez 17:14, 6 November 2011 (UTC)

Different person here: Just a request for something to add to the wiki. In order to light a portal using something on fire (as opposed to flint and steel when in a pinch), the block must be placed next to a space within the portal and not within the portal itself dregt playing 1.1

Do Endermen move obsidion that make portals?
i spent forever to find enough obsidian to make a portal to nether and there were three endermen walking by my house witch is by my portal; so i want to know if they'd break the portal Killrbladez 17:26, 6 November 2011 (UTC)
 * Enderman --HexZyle 02:11, 7 November 2011 (UTC)

Liquid deactivation nerfed in 1.0.0
Since version 1.0.0 portals cannot be shut off using liquid. This is not true. You can deactivate a portal by placing water directly in the frame with a bucket. However, it is true that flowing liquid cannot deactivate a portal. The page should be edited to reflect this.70.112.39.37 22:35, 30 November 2011 (UTC)Applejacks

Im sorry but this is just bullshit. Notch, well jeb now, needs to fix this. it basically ruined the only, Flip-of-a-switch portal design.

Trivia
I've just removed some old/incorrect trivia:


 * Zombie Pigmen grunts can be heard through portals.
 * In order to deactivate a portal without destroying it, pour a bucket of water or lava next to the portal, so that the liquid flows into it. Water is only viable in the overworld, but lava works to shut down portals in either world.
 * If trees are planted near a portal, the full grown trees may take up one of the portal blocks. If this is the case, the horizontally adjacent portal block will be turned 90 degrees, such that you can see through the portal block on either side of it. However, the Nether side of the portal will remain the same. Upon returning, the portal block will still be flipped.
 * As of 1.0.0 update, nether portals will make nearby water freeze.

A few quick tests should demonstrate that none of these are true.


 * Sometimes Endermen can come out of nether portals, if they do at day-time they will randomly teleport and then vanish.

I don't know how to test this one, but unless there is evidence to the contrary, it should be left out.

JohnnyAlpha 19:27, 28 November 2011 (UTC)

I was just working on my new world today because a computer crash deleted my old world. I decided to make a portal, and then when trying to return to the normal world, it instead took me to the old world that got deleted. I think it may be something to do with loading the old chunks maybe? But now I can't return to the newly created world, I think it's overwritten it... Any suggestions? (And I think this need's to be added to the wiki under bugs maybe, but I'm new to wiki so...)

same portal used over distance of over 1k
I built a portal in one location and soon grew tired of where it put me in the Nether. I built another portal over 1,000 meters away as proved by the fact that I received the "On A rail" achievement going from one base to the other. But, the new portal sent me to the old lame area in the Nether again. Returning through that portal returns me to my original base as it always has. I guess it's nice to be able to quickly get from the second base to the first, but like I said I already built a railway. Is there any way to fix this without committing suicide in the Nether? Noit 19:13, 15 February 2012 (UTC) The reason I'm putting this here is the numbers on this page led me to believe the distance was well far enough to act autonomously. Maybe the numbers are wrong or there is something else happening not covered on this page.Noit 19:15, 15 February 2012 (UTC)

I also built a second nether portal over 1000 overworld blocks away from my first and it always takes me to the same first portal in the nether like you, and returning brings me back through the original portal as well. personally i'm getting so fed up with all these bugs i'm ready to pull my hair out!! this game has become a nightmare, a literal bane of my existence with how many versions i've had to scrap, i've sunk so much time into it only for the game to be irreparably broken, twice to the point where the map can't be salvaged. i recommend all of my friends not to buy the game until it's worth a damn cent... more to the point, the algorithm NEEDS to be rewritten, because even if it works as planned it's a STUPID system.

New world height
Has anyone tested the comportment of portals built over 128? The page still talks about both worlds being 128 high and the Y axis being mapped 1 to 1. Will it put you over the top bedrock layer? Vokhev 18:34, 5 March 2012 (UTC)
 * In SMP 1.2.3, I created a portal just above sea level and it put me on top of the upper bedrock in the Nether. My guess is that step 3 of "Linkage between Overworld and Nether" doesn't ignore the new empty upper half of the Nether. Presumably, the 33 X 33 space centered on my portal location was mostly filled with solid blocs and the first empty space the game found was above 128. Vokhev 17:00, 6 March 2012 (UTC)
 * In 1.2.3 I built a portal in the overworld at height ~ 123 and it initially became a one-way, but then I broke the other portal in the overworld causing the one-way as well and the old nether portal, and it generated a new portal above nether bedrock. 173.178.52.33 05:03, 7 March 2012 (UTC)
 * After a lot of hassle, i managed to get a portal inside the nether and to reach the coordinates corresponding to my overworld portal. It does seem like most the chunks around this place are mostly filled with netherack which would tend to confirm my earlier assumption for the reason my portal ended up over the bedrock. Vokhev 15:32, 7 March 2012 (UTC)
 * I built into the sky and constructed a portal at around 230 height. I can't get it to it from a nether portal I build in the nether though.  Going to the place in the nether I would expect to connect to my sky-portal, it instead makes a portal in a cave. --205.185.94.166 19:42, 7 April 2012 (UTC)
 * In SMP 1.2.3 I built my portal at 200 and after a fix the cordination of the portal in nether ( x and z not y) my portal was working fine. but i don't know why in 1.2.5 doing the same thing in a other area. look like it dosent work i try evry thing, diffrant height in overworld and in the nether...not working because went i returne from the nether they keep creating a new portal in a overwolrd if i use the new portal created it will work fine but not  in the height desir ( a round 50 height ground floor ) VALNAR

Texture
Where is the texture for the portal block? On the Texture pack page it says that a weird, blue square is the portal texture, but where is the actual purple block?

P.S. sry for my bad english, I'm from Sweden

''Actually, your English is perfect. I am wondering the same thing though. I think I read that it is generated with code, and therefore unchangeable without a mod.''

I think (actually, quite sure) that it is because of animations. The blue block is the actual portal, just that it becomes animated once placed. With mods such as optifine, if you switch off portal animations, the block changes from swirls to a simple plain blue one, which should be the one you saw.120.63.59.190 12:58, 8 June 2012 (UTC) Arv

Portal in a tree
An interesting thing happened to me, in 1.2.5 I built a portal in the Nether and came out atop a swamp tree. Not on wood but on leaves, one block into the top of the tree. There was land around below, though it was a small peninsula. Does this happen commonly? Pareidolon 19:36, 13 April 2012 (UTC)

Where to build your first Nether Portal.
I only bring this up because I heard someone on a YouTube Tutorial mention that and I quote "I used to build my Nether Portals above ground but now I do it underground, obviously" For the tutorial he built a Nether Portal above ground and didn't say why you 'should' build it underground instead.

So does anybody know why this is? And why I shouldn't build it in or near my house?