End portal

End Portal are naturally occurring structures that are used to travel into The End. They can only be found in strongholds, and consist of a horizontal frame of 12 Ender Portal Frame blocks, organised into a roughly square shape, five blocks wide, five blocks long. Upon placing an Eye of Ender in every Ender Portal Frame block of a specific portal, the portal activates, creating 9 Ender Portal blocks inside the frame, and allowing the player to access The End. The End Portal is part of the 1.9 pre-release 3 update, but was nonfunctional until pre-release 4. The official release for the Portal was to be 1.9 (1.0.0). Which has now been released.

End Portals are found horizontally within the portal room of a stronghold, over a pool of lava, with a staircase leading up to the portal, and a Silverfish spawner. Some of the portal frame blocks already have Eyes of Ender in them (usually 1-2), while the rest do not.

Behaviour
Stepping into an activated End Portal immediately opens up a loading screen, and transports the player to The End, leaving no time to back out, unlike the Nether Portal. Upon entering The End, a five by five horizontal platform of obsidian is spawned at (0,72,0), often in midair, and the player is placed on top of it. Due to the lack of a return portal being generated, the Ender Portal is one way and the End cannot be escaped from without either dying, or by killing the Enderdragon.

The black portal blocks emit light of level 15, which is as powerful as Glowstone and is the brightest light level there is. It only takes one block of portal to teleport to The End. Through the use of an inventory hack, you can place these portal blocks anywhere, and they will still function as if they were a complete portal. The only exception to this is in The End, where the portal blocks will decay instantly. Fluids flowing through the portal will destroy all the portal blocks (but not the portal frame blocks) it comes in contact with; however, if even one portal block remains, it may still be used to access The End.

As of beta 1.9 pre-3, the Ender Portal frame block could be broken by an explosion. As of beta 1.9 pre-4, it cannot be destroyed at all in any way, except with mods, hacks and creative mode.

Activating the Ender Portal will destroy any blocks located in the center 3 x 3 square, where the resulting Ender Portal blocks will be. They will even destroy Bedrock or another Ender Portal Frame (though neither of these items will occur there naturally). It will destroy fluids, though if the source block is not also removed, then it will immediately flow back through. The destruction of the blocks does not make any sound, and applicable blocks do not drop as resources (exceptions being the top part of a door or the extended part of a vertical piston, which both destroy the whole object and drop them as resources), and events sometimes triggered by block destruction will fail to occur: TNT will simply disappear without detonating, and Block 97 will fail to spawn a silverfish. However, Chests, Dispensers, Furnaces, and Jukeboxes will all drop their contents. Strangely if you try to sleep in the end there will be an explosion and a pit of fire where you might die.

Trivia

 * End portals are very thin, and only the top face is solid. You can jump through the bottom face, and not the top face.
 * You can see through the bottom of an activated end portal because the portal substance is not visible from the bottom.
 * The portal does not deactivate if you somehow manage to destroy the frame.
 * Like Nether Portals, the end portals can be deactivated with water.
 * However, unlike the nether portal, an end portal cannot be reactivated.
 * The non-solid portal blocks can be destroyed in creative mode by punching them.
 * When an ender portal frame block breaks, it makes the same noise as breaking glass.
 * If the player somehow obtains the necessary Ender Portal Frame blocks, it becomes possible for them to build their own portal. However, the portal frame block that last receives the Eye of Ender must be oriented the correct way, placed from inside the circle and facing out.  Oddly, the orientation of the other 11 frame blocks does not matter.
 * Player-made portals may be created adjacent to one another, sharing blocks. However, if they are sharing anything except the corners, the last-placed Eye of Ender may not be in a block 1 block diagonal to or up to 2 blocks adjacent to any Frame block not belonging to that portal.  They may, however, be freely stacked vertically.
 * In Minecraft 1.0.0 there is a glitch where only 3 sides of the incomplete portal will spawn. The player will be unable to go to The End and will have to find a complete portal. This may not be a glitch, as strongholds are very obviously decayed.
 * End portal blocks themself are a darker version of one of the phases of water (if looked closely).
 * End portals give off light at level 15, including the frame block itself.
 * Unlike Nether Portals, you are transported exactly when you touch the portal.