Ocean Monument Guide — How to Raid, Defeat Guardians & Get Sponges

Ocean Monuments (also called Ocean Temples) are massive underwater structures made entirely of Prismarine and guarded by Guardians and 3 Elder Guardians. They're the only source of Sponge blocks (for water removal), Prismarine building materials, and the Dark Prismarine needed for Sea Lanterns.

📐 See our Methodology page for the complete verification process, editorial standards, and update cadence.

This guide covers everything: how to find monuments, how to prepare for underwater combat, how to defeat all 3 Elder Guardians, how Mining Fatigue works, the complete loot table, and how to set up a Guardian farm for unlimited Prismarine.

How to Find Ocean Monuments

Method 1: MC Seed View

Use our Ocean Monument Finder to see every monument on your seed with exact coordinates.

Method 2: /locate Command

/locate structure minecraft:monument

Method 3: Cartographer Explorer Maps

Trade with a Cartographer villager (level 3+) for an Ocean Explorer Map. The map marks the nearest monument with a gold icon. This is the best vanilla method without commands.

Method 4: Explore Deep Ocean

Monuments only spawn in deep ocean biomes (not regular ocean). Sail by boat looking for the dark prismarine structure below the surface. Night Vision potions make spotting them much easier.

Preparation — Essential Gear

Item	Priority	Purpose
Respiration III Helmet	Critical	Extends breath from 15 sec to 60 sec underwater
Aqua Affinity Helmet	Critical	Normal mining speed underwater (otherwise 5x slower)
Depth Strider III Boots	Critical	Normal walking speed underwater
Water Breathing Potions (8 min)	Critical	Infinite breathing — use Pufferfish + Nether Wart + Redstone
Night Vision Potions	High	See clearly underwater — essential for navigation
Milk Buckets (3+)	High	Remove Mining Fatigue from Elder Guardians
Trident (Impaling V)	High	Best underwater weapon — Impaling V shreds Guardians
Diamond/Netherite Armor	High	Protection against Guardian lasers
Doors or Torches	Medium	Create air pockets inside the monument
Sponges (if you have any)	Medium	Drain rooms for easy exploration

Monument Layout & Navigation

Ocean Monuments are 58×58×23 block structures made of prismarine, dark prismarine, and prismarine bricks. They contain:

Area	Location	Contents
Entrance	Front face (identifiable arch)	Main entrance with guardian patrols
Wing Rooms (2)	Left and right sides	Each contains 1 Elder Guardian
Top Room	Top center (penthouse)	1 Elder Guardian + gold block treasure
Treasure Room	Center core	8 gold blocks encased in dark prismarine
Sponge Rooms	Random locations (0-6)	Wet Sponge blocks (if present)
Corridors	Throughout	Guardian spawns, interconnecting passages

Navigation Tips

• Enter from the top — The roof is easier to break through than finding the entrance while fighting Guardians
• Place doors for air — Doors create air pockets in Java Edition. Place them on walls to breathe
• Kill Elder Guardians first — Prioritize clearing all 3 Elders before exploring for loot/sponge rooms
• Mark explored areas — Place torches or unique blocks to avoid getting lost in the maze-like corridors

Elder Guardian Combat

Each monument has exactly 3 Elder Guardians — 1 in each wing room and 1 in the top room. They're mini-bosses:

Stat	Elder Guardian	Regular Guardian
Health	80 HP (40 hearts)	30 HP (15 hearts)
Laser damage	8 damage (Hard)	6 damage (Hard)
Mining Fatigue	Yes (applies every 60 sec)	No
Spike damage	2 (when attacked)	2 (when attacked)
Drops	Prismarine Shards, Crystals, Sponge, Fish	Prismarine Shards, Crystals, Fish
Count	3 per monument (fixed)	Many (respawn)

Combat Strategy

1. Drink Water Breathing + Night Vision before entering
2. Rush the Elder Guardian — it charges a slow laser beam. Close the distance before the beam locks on
3. Hit with Trident (Impaling V) — deals massive extra damage to aquatic mobs. 3-4 hits kill an Elder
4. Drink Milk immediately after killing each Elder — removes Mining Fatigue so you can mine blocks normally
5. Repeat for all 3 Elders — once all are dead, Mining Fatigue stops completely

Mining Fatigue — How to Counter It

Mining Fatigue III is applied every 60 seconds by living Elder Guardians. It makes block breaking extremely slow — a Diamond Pickaxe takes as long as fists normally would.

Counter Strategies

• Milk bucket (best method) — Drinking milk removes Mining Fatigue immediately. Bring 3+ buckets
• Kill all Elder Guardians — Once all 3 are dead, no more Mining Fatigue is applied
• TNT — TNT still destroys blocks normally even with Mining Fatigue. Place TNT and ignite with flint and steel
• Efficiency V + Haste II Beacon — With maximum mining speed buffs, you can still mine slowly through Mining Fatigue. Not practical but possible.

Sponge Rooms & How Sponges Work

Sponge blocks are exclusive to ocean monuments and are incredibly useful for large-scale water removal.

Finding Sponges

• Each monument can have 0 to 6 sponge rooms — not guaranteed
• Sponge rooms contain wet sponge blocks on the ceiling (usually 20-30 per room)
• Elder Guardians also drop 1 wet sponge each on death (guaranteed)

How Sponges Work

• Place a wet sponge in a furnace to dry it → becomes a sponge
• A dry sponge absorbs up to 65 water blocks in a 7×7×7 area when placed
• After absorbing, it becomes a wet sponge again — smelt to reuse
• Sponges are the most efficient way to drain underwater areas, guardian farms, or ocean bases

Loot & Rewards

Item	Source	Use
Prismarine Shards	Guardians, Elder Guardians	Craft Prismarine blocks, Sea Lanterns
Prismarine Crystals	Guardians, Elder Guardians	Craft Sea Lanterns (best underwater light)
Sponge	Sponge rooms, Elder drops	Water removal (65 blocks per use)
Gold Blocks	Treasure room (8 blocks)	72 gold ingots total
Tide Armor Trim	Elder Guardian drop	Exclusive armor customization
Raw Cod/Salmon	Guardian drops	Food source

Basic Guardian Farm Setup

Guardian farms are among the most rewarding automated farms in Minecraft, producing Prismarine, Sea Lanterns, XP, and fish passively.

Concept

1. Drain the monument area — Use sponges to remove all water within and around the monument's bounding box
2. Build a spawning platform — Replace the monument with water channels at Y=62 where Guardians can spawn
3. Funnel with water — Use water streams to push spawned Guardians to a central point
4. Kill chamber — Magma blocks, campfires, or lava for automated killing
5. Collection — Hoppers + chests below the kill chamber collect all drops

Best Seeds with Monuments Near Spawn

Frequently Asked Questions