An ocean monument is the big prismarine structure sitting at the bottom of deep ocean biomes in Minecraft. From the surface it looks like a glowing blue-green temple, and it is the only place guardians and elder guardians spawn naturally.
Players raid monuments for three things: wet sponges that soak up water, blocks of gold hidden in the center, and a steady supply of prismarine and sea lanterns for building. The catch is that the monument fights back. Elder guardians hit you with a curse that slows your mining to a crawl, and ordinary guardians pepper you with laser attacks the whole time.
This guide covers where monuments spawn, how to get inside and survive, how to shut down the mining curse, and what you actually walk away with.
What is an ocean monument?
An ocean monument is a large naturally generated structure built entirely from prismarine, prismarine bricks, and dark prismarine, and lit by sea lanterns. It has a tall central section flanked by two wings, plus an entrance area and support pillars underneath. The whole thing is fully submerged, so everything you do inside happens underwater unless you carve out air pockets.
Each monument is home to guardians, which spawn continuously in the water around and inside it, and up to three elder guardians, which are placed when the monument generates and never respawn once killed. The elder guardians are the real obstacle. Guardians are just the chip damage on the way in.
Where ocean monuments generate
Monuments only spawn in the deep ocean family of biomes: deep ocean, deep cold ocean, deep frozen ocean, and deep lukewarm ocean. They need the extra depth, so you will never find one in a regular ocean, a warm ocean, or any shallow water. If the water above the monument is only a few blocks deep, you are looking at the wrong biome.
They generate a fixed distance apart, so once you find one, others tend to sit hundreds of blocks away in various directions. A single monument is usually all you need for a first trip.
How to find one
The fastest way is to sail across deep ocean and watch the seafloor. Sea lanterns give off light that shows through the water, so a monument reads as a cluster of glowing blocks in the dark below you. Bumping up your render distance and playing with brightness turned up both help a lot.
If you would rather not search by hand, an ocean explorer map points you to the nearest monument. Cartographer villagers sell these maps, and the map marks the monument with a small icon so you can sail straight to it.
Getting inside and staying alive
The monument is deep, dark, and full of things shooting at you, so gear matters more here than at almost any other structure.
Bring a way to breathe. A potion of water breathing buys you eight minutes per bottle, and a helmet enchanted with Respiration stretches how long you last on a single lungful. Placing doors, signs, or a small pocket of blocks against a wall traps an air bubble you can duck into.
Bring a way to see. Underwater is murky even in daylight, so a potion of night vision makes the inside of the monument readable instead of a blue smear. Aqua Affinity on your helmet removes the underwater mining penalty, which you will want later.
Bring a way to move. Depth Strider boots or a Dolphin’s Grace effect cut down on how sluggish swimming feels. Getting stuck fighting a current while three guardians line up shots is how trips go wrong.
A conduit is the single best tool for a monument raid. Built from a heart of the sea wrapped in eight nautilus shells and framed with prismarine, an active conduit gives you water breathing, night vision, and faster underwater mining inside its range, and it damages hostile sea creatures nearby. You can build the frame out of prismarine mined from the monument itself.
Guardians and elder guardians
Guardians are spiky fish mobs that swim through the monument and the water around it. Their main attack is a laser: the beam locks onto you, charges up for a second or two, then deals damage when it fires. Breaking line of sight or ducking behind a wall cancels the shot. They also have spikes that hurt you if you touch them while extended, so meleeing one head-on costs you health.
Guardians drop prismarine shards, and sometimes prismarine crystals or raw cod. Those shards and crystals are what you craft sea lanterns and prismarine blocks from, which is why guardian farms built on top of drained monuments are so popular.
Elder guardians are the bigger, tougher version. There are three per monument: one in the top central room and one in each wing. They hit harder, take more killing, and drop a guaranteed wet sponge along with the usual prismarine. They do not respawn, so every elder guardian you kill is gone for good.
Mining fatigue and how to beat it
When you get close to an elder guardian, it curses you. A ghostly image of its face flashes on your screen with a sound, and you get Mining Fatigue III for five minutes. This effect tanks your mining and attack speed so hard that breaking a single block takes ages. It exists specifically to stop you from quickly tunneling to the gold and sponges.
You have a few ways to deal with it:
- Kill all three elder guardians. Once they are dead, nothing reapplies the curse, and it wears off on its own after five minutes.
- Drink a bucket of milk to clear the effect instantly. This works, but any living elder guardian in range will simply curse you again, so milk is a stopgap, not a fix.
- Use TNT. Explosions break blocks at full speed no matter how bad your mining fatigue is, so players often blast through prismarine to reach the treasure instead of mining it by hand.
The clean approach is to hunt down the elder guardians first, then loot at your leisure. The messy-but-fast approach is to bring explosives and dig straight in.
What’s inside: sponges and gold
Two prizes make the raid worth it.
The first is sponges. Some monuments generate a sponge room packed with wet sponges, and every elder guardian drops one wet sponge when it dies, so you leave with at least three even if there is no room. Smelt a wet sponge in a furnace to dry it out, and a dry sponge soaks up a large volume of water the moment you place it near a source block. Sponges are the tool that makes draining the whole monument possible.
The second is gold. The top central room, guarded by an elder guardian, hides blocks of gold behind dark prismarine. Mining through to reach them is exactly what the mining curse is trying to prevent, which is why the gold room is the classic reason to clear the elder guardians or bring TNT.
What to do with a monument after you clear it
Once the elder guardians are dead, a monument becomes a resource you can keep coming back to.
Many players drain the whole structure using sponges, turning it into a dry, walkable building you can convert into a base or a guardian farm. Because ordinary guardians keep spawning in the water, a farm built around the monument gives you a renewable source of prismarine shards, prismarine crystals, and cod, which means renewable sea lanterns and an endless supply of building blocks.
Even without a farm, the monument is a mine of prismarine, prismarine bricks, dark prismarine, and sea lanterns for anyone who likes building with those blocks. Dark prismarine in particular is annoying to craft in bulk, so hauling it out of a monument saves real time.
Tips and common mistakes
Do not try to mine the gold before dealing with the elder guardian watching it. You will stand there for half a minute per block while guardians shoot you in the back. Clear the elder guardians or bring TNT.
Watch your breath meter constantly. More players die to drowning in a monument than to the guardians themselves, usually while distracted by a fight. Keep an air pocket or a water breathing timer in mind at all times.
Bring more milk or a conduit than you think you need. A conduit that covers the area removes most of the breathing and visibility problems and chips away at guardians for free while you work.
Mark your entrance. The inside of a monument is a maze of identical prismarine corridors, and it is easy to lose track of the way out when your screen is dark and something is shooting at you.
Java and Bedrock differences
The monument itself, the elder guardian curse, and the loot are the same in both Java and Bedrock. The main practical difference shows up in guardian farms: spawn rules and optimal farm designs differ between the two editions, so a farm layout tuned for Java will not always perform the same on Bedrock and vice versa. For a straightforward raid, though, you can treat both editions the same.
Frequently asked questions
What biome do ocean monuments spawn in?
Only the deep ocean variants: deep ocean, deep cold ocean, deep frozen ocean, and deep lukewarm ocean. They never spawn in regular or warm oceans.
How many elder guardians are in an ocean monument?
Three. One sits in the top central room and one in each of the two side wings. They do not respawn once killed.
How do you get rid of mining fatigue in a monument?
Kill all three elder guardians and wait five minutes for the effect to fade, or drink a bucket of milk for an instant clear. Milk only holds until a living elder guardian curses you again, so killing them is the permanent fix.
Does every ocean monument have sponges?
Not every monument has a sponge room, but every elder guardian drops one wet sponge, so you always leave with at least three sponges even from a monument with no room.
Is there gold in every ocean monument?
Yes. Gold blocks are hidden behind dark prismarine in the top central room of every monument, guarded by an elder guardian.
Do guardians respawn?
Ordinary guardians keep spawning in the water as long as the conditions are right, which is what makes guardian farms work. Elder guardians are placed once at generation and never come back.
What do guardians drop?
Prismarine shards, plus a chance at prismarine crystals or raw cod. Those drops are used to craft sea lanterns and prismarine blocks.
Is it worth it?
For a first raid, the gold and the pile of sponges pay for the trip on their own. The bigger payoff comes later: a cleared monument is prime real estate for a guardian farm, and that turns a one-time dungeon into a renewable source of sea lanterns and prismarine for as long as you want to run it.