Tutorials/Defeating a monument

Monuments are dangerous for unprepared players, as they have many dangers, including guardians, elder guardians, and many rooms that are easy to get lost in.

Reasons for defeating a monument
There are a several benefits of defeating a monument:
 * To get the 8 gold blocks in the core.
 * To get sponges
 * To obtain sea lanterns, and prismarine, which can otherwise be obtained only from underwater ruins.
 * To set up a guardian farm, which allows you to get even more prismarine, sea lanterns, and fish.
 * For the experience you get when killing guardians.
 * To establish an underwater home (or even an underwater village).
 * For playing mini games with your friends.
 * For the challenge.

Dangers
The most common mob within the monument are guardians. They swim quickly, have health, and have two ways to damage the player:
 * A laser is their primary offensive attack. It takes several seconds to charge, emitting a distinctive sound and changing color from purple to yellow in the process, and does points of damage when the charging completes.
 * There is no way to dodge the laser, but the guardian must maintain line-of-sight during the charging process. If you can get behind a wall or pillar, the attack is canceled and deals no damage. Circling narrow pillars therefore can be used to circumvent multiple attacks from all sides.
 * The laser has a maximum range of about 15 blocks. If you can get far enough away before the charging completes, the attack is cancelled and deals no damage.
 * If the player gets too close to the guardian, it is liable to abandon the attack and swim away.
 * Guardians also have a natural Thorns-like defense. If attacked while their orange spikes are extended, the attacker takes damage.

Each monument also contains three elder guardians. They have health and a somewhat stronger laser attack which deals  points of damage, but move slowly and infrequently. They also inflict any player within 50 blocks with Mining Fatigue III for 5 minutes. $$, the elder guardians check for nearby players to afflict every 60 seconds. $$, they afflict players immediately without waiting, so if you try to defeat a monument in Bedrock edition, you can count on being afflicted with Mining Fatigue 100% of the time until all three elder guardians are killed.

Under the Mining Fatigue, you take about 370 times longer to break blocks and your attack speed is reduced by 30%. When an elder guardian inflicts you with Mining Fatigue III, then you could drink a bucket of milk. However, drinking milk also removes Water Breathing, and you just get Mining Fatigue soon afterward (immediately in Bedrock edition) anyway. Wait until you have defeated all 3 elder guardians before drinking milk. Until then, simply avoid breaking blocks, and travel only through pre-made passages. If you must place blocks, such as in the case where you need to run around a pillar to break line of sight with the guardians, use slime blocks, honey blocks or TNT. Slime blocks, honey blocks and TNT are breakable instantaneously even under the effect of Mining Fatigue. There are still ways to brute-force your way into a monument, which is covered later.

Be sure to kill the elders in a manner that counts as a player kill so that they drop wet sponges, which can be smelted in a furnace or placed in the Nether to make dry sponges. A dry sponge, strategically placed, is a quick way to clear out a large volume of water.

Locating a monument
Monuments are found only in deep ocean biomes, so you'll need to find an ocean and explore it. Being underwater, the monument may be difficult to see, but the sea lanterns are distinctive and are easily visible if you're looking for them, especially at night. The top of the monument is generally close to the surface, making it possible to search for it in the day, however it is easier to miss. You can also listen for the sound of guardian lasers as they attack squid.

These seeds tend to be island survival worlds; it is possible to defeat the nearest monument, but see Tutorials/Island survival for survival tips.
 * The right seed
 * $$, the seed picker includes a world called "Ocean Monuments Ahead", which has multiple monuments reasonably close to the spawn point. In fact, you can easily see one of the monuments from the northeastern shore of the small island on which you spawn.
 * $$, three simple seeds spawn you close to an ocean monument in 1.17: 101 (the closest), 400, and 555555.


 * Survival searching
 * Using a boat is the easiest way of searching for a monument, especially looking for sea lanterns at night.
 * A potion of Night Vision helps to see the monument from above the water.
 * If you have enough, ender pearls can help travel large stretches of water quickly. You can also use a Trident enchanted with Riptide.
 * Use an Ocean Explorer Map from the cartographer villager.
 * Use an Elytra in late game.


 * Other Methods
 * Online tools, such as Chunkbase can be used to locate monuments based on the world seed.
 * Using a resource pack with clear water textures makes it easier to see the monument.
 * Using the command . You can re-create the world from the same seed in creative mode for locating and map-making.

Equipment checklist
Equipment that is particularly helpful when infiltrating a monument:
 * Any armor; it is actually possible to defeat a monument without armor, but armor allows you to have helpful enchantments. Wearing a turtle shell instead of a helmet supplies some additional water breathing. If possible, obtain these armor enchantments (which can be found on gold armor dropped in a drowned farm):
 * Respiration III allows you to spend less time worrying about your air supply.
 * Aqua Affinity speeds up mining blocks underwater, which helps with a quick break-in before Mining Fatigue is applied.
 * Depth Strider III increases your movement speed underwater.
 * Protection reduces damage from the guardians' lasers and thorns. Specialized defenses like Projectile Protection does not mitigate the guardians' attacks.
 * A strong sword, optionally enchanted with Sharpness, Looting, and Mending or Unbreaking. Avoid using axes because they are slower and lose 2 durability if used to attack a mob.
 * Ranged weapons (pick whatever is convenient, not all are needed):
 * A trident is not required in order to defeat an ocean monument, but it makes the process significantly easier, especially when it is enchanted with Impaling V and Mending. Loyalty is also a good enchantment for your trident as it allows you to throw it without losing it.  Throwing the trident also has the additional benefit of bypassing the thorns effect from guardians as well as ignoring the 30% reduced attack speed, as both penalties only affect melee combat.
 * A bow, particularly when enchanted with Power, is effective underwater at close range, and can be used easily to kill the elder guardian at the apex of the monument after drying out the "gazebo" area and shooting through a hole in the floor. Bear in mind that arrows are slowed down significantly while underwater, and as such cannot be fired from medium or long distances.
 * A crossbow can fire arrows like a bow, and the arrows from a crossbow are faster and more damaging than that of a bow. However, underwater there is little difference. Crossbows can also fire firework rockets, which, if crafted with  firework stars, explode upon hitting a mob and do not have their velocity changed by the water, unlike arrows.
 * Food is essential since you want to regenerate from damage you take. If you have a fishing rod, the easiest source of efficient and nutritious food is cooked cod or cooked salmon. Steak or cooked porkchops stack and restore each. Other great foodstuffs, such as golden apples and golden carrots, comes at a highly expensive cost, and dried kelp is a fast food but only restores . If you can, bring Enchanted Golden Apples.
 * Slime blocks, Honey blocks and TNT are very useful for walling off areas you don't want to go to yet, creating barriers to break line-of-sight, and otherwise marking your path, since they can be broken instantly even while affected with Mining Fatigue III.
 * If you can't get enough slime blocks, honey blocks and TNT, you might also try wooden doors and trapdoors, since they can be opened and closed. Also, doors and trapdoors can make an air pocket, which can replenish air in an emergency.
 * Soul Sand is an option as of 1.13 as they emit air bubbles that can be used to replenish air supplies. They can also be used to help ascend to higher parts of the Monument if strategically placed. Their only downside is that they jam you to the ceiling while being used so the best strategy is to use them in safe rooms and make short excursions to clear ahead, then placing another when you feel another safe area has been cleared.
 * Magma blocks also provide air bubbles to replenish air, but forcibly drag you downwards to them as you stand in the column. You also take damage if you stand on them without sneaking.
 * Potions of Water Breathing allow you to ignore your air supply and concentrate on hunting the Elder Guardians and navigating the monument.
 * Potions of Invisibility, while wearing only boots with Depth Strider III, let you sneak past the Guardians to fight the Elder Guardians without interruption. Do not wear other armor or the invisibility does nothing.
 * Potions of Night Vision can help with seeing in dark areas of the monument.
 * Potions of Strength greatly increase your melee damage.
 * Milk is useful only in Java Edition. It removes the Mining Fatigue effect, allowing you to mine through the walls of the monument to reach your destination easier. However, this also negates your beneficial potion effects, and the elder guardians re-apply Mining Fatigue within 60 seconds (or instantly in Bedrock Edition). Setting up a conduit removes the risk of getting rid of Water Breathing when drinking milk.
 * Golden Apples give you 2 extra hearts and Regeneration II for 5 seconds - great when you're coming under heavy fire.
 * A TNT block and a gravity-affected block such as gravel, as well as a way to light the TNT. TNT by itself is useless underwater. However, if you place a gravity-affected block on top of the TNT before lighting it, the gravity-affected block displaces the water inside the TNT entity, allowing it to possibly blow a hole in the monument.
 * If you're planning to collect sea lanterns, a tool with Silk Touch collects them whole.
 * If you do decide to dry out the monument, sponges are extremely useful for that purpose. In that case, you'll also want a furnace and fuel to be able to reuse them.
 * Ladders can also come in handy for getting up and down within the monument once the water is gone.
 * A conduit makes looting the monument easier to do as one set on the top of the monument grants permanent water breathing and better vision throughout the complex, as well as faster mining speeds. If a complete frame is established, this can also attack the Guardians and turn the monument into a Guardian farm later on.
 * Using a and  can help block off walls and allow fast mining due to how fast hoes can harvest leaves. Iron or higher instantly breaks leaves.

Defeating the monument
The first step is to get inside the monument, which can sometimes be difficult as guardians spawn outside the monument and will attack you. There are several ways you can get in:
 * Go in the front door. You might throw an ender pearl to get there quickly, dive from above, or run along the seafloor with Depth Strider III-enchanted boots.
 * Mine through the roof above the elder guardians' rooms. It helps to drop blocks of sand around the gazebo at the top to build a quick bunker around the site. Clear the water out using slime blocks, dig a hole in the roof and shoot the top elder guardian with a bow to kill it and get your first sponge, and work your way down. In Java Edition, use milk to counteract the Mining Fatigue. In Bedrock Edition, milk removes Mining Fatigue for no more than one second so milk isn't useful; instead, use the correct tool (shovel for sand, pickaxe for stone, hoe for sponges, etc.) for each block you mine (gold tools are most efficient but wear out quickly), preferably enchanted with Efficiency, and you can actually make progress under constant Mining Fatigue.
 * Tunnel up from below. For this you'll almost certainly need milk to counteract the Mining Fatigue. An efficient way to use this method would be to bring a cow and a few buckets. One of the safest ways to do this is to mine below the ocean's floor until you get to below the structure. From there you can mine up one of the 4x4 columns using a 2x2 spiral staircase, or simply using ladders if you want. Ideally, you bring a cow and a few buckets to a base you make underneath the monument, that way you can get milk much quicker. It takes a lot of milk.
 * In Java Edition, if the player creates a platform over the apex of the monument, TNT can be activated and dropped down and an elder guardian can be killed without any structural damage. If structural damage is preferred, sand or gravel can be dropped after the activated TNT, which will make the TNT explode inside the sand block, and structural damage will be dealt. This method can be repeated over the left and right wing of the monument, to kill the rest of the elder guardians. This can also be done underwater, by placing a sand/gravel block on top of the placed TNT before detonation.

Once inside, it can be advantageous to set up a base of operations. Doors or slime blocks can be used to seal any entrances to a chosen room, and sponge blocks can be used to quickly clear it of water. Then you might move in resources such as furnaces for drying sponges, chests to hold potions and other supplies, a bed in case you die, a nether portal for easier access via the Nether, and a cow for milk refills.

A conduit can be set up in a 3 block high undrained room for up to 31 blocks worth of Conduit Power merely by placing a slime block, honey block or block of TNT on the floor one block diagonally in from the corner, placing the conduit on top and breaking the block. This removes any worries about air and helps speed up breaking through the prismarine if that is necessary.

Your goal inside the monument is to take out the elder guardians to eliminate the Mining Fatigue III that hinders your ability to obtain the resources from the monument. There are three per monument: one in the "penthouse" at the very top and one in each of the wings flanking the main entrance. The elders themselves are not extremely difficult if you're prepared with strong armor and weapons, since they move and attack relatively slowly, but finding them within the maze can pose a challenge. It might help to wall off dead ends as you investigate them, and note that the wings are connected by a long hallway around the back of the monument that bypasses the maze. Alternatively, you could simply mine through the ceiling of the elder guardians' rooms with a high-level Efficiency pickaxe, to counteract Mining Fatigue.

After that is done you can simply raid the monument of its sea lanterns, sponges, prismarine, and gold and leave. Alternatively, you can turn it into a base or a guardian farm. Now that Mining Fatigue is no longer an issue, you can use any method you'd like to accomplish this. If you were lucky enough to find a sponge room (or three), the sponges will be particularly helpful in this task, as the sponges will soak up a lot of the water. Even if you did not find a sponge room, you can use the sponges from the elder guardians, or previously-obtained sponges from other monuments.

Aftermath
Once you are done raiding, you can do these things:


 * Leave. Elder guardians won't respawn but guardians will respawn.
 * Turn it into a guardian farm. Guardian farms produce tons of experience and prismarine. You also get fish and ink sacs as byproducts. If your guardian farm uses fire to kill the guardians, all the fish from one hour of AFK can feed a player for a long time and possibly feed an entire server. You can write down the coordinates or lay a path to remember the location of the monument.
 * Turn it into a base. It is recommended to drain the ocean monument and all guardian spawning spaces. The building is very large and you can add a lot to it. Add all necessary items, such as crafting table and furnaces, enchanting and anvil + grindstone, blacksmith area with smithing table, and villager trading hall. You can also build a guardian farm in your base, but it will be smaller and less efficient. If your guardian farm doesn't use fire to kill the guardians, you get raw fish, which you can sell to fisherman villagers for a good source of emeralds.
 * Turn it into a village, drain all the water using sponges and move in villagers. Add beds and job site blocks for the villagers, and a different villager can sleep in each room of the monument. Be sure to keep an iron golem in the village, so the guardians don't scare the villagers away! Guardians don't attack iron golems so one iron golem is fine, but build a barrier around the monument to the ocean surface so drowned cannot come in.
 * Destroy the monument. Use a pickaxe and water breathing potions to mine all the prismarine blocks. Having Aqua Affinity and Respiration enchantments on your helmet can make this easier.