Ocean Monument
Ocean Monument is a generated structure in Minecraft. It is home to Elder Guardian and Guardian.
Ocean Monument is a large, rare underwater structure that generates exclusively in deep ocean biomes and their variants. It stands as the only natural source of sponges in the game and one of just two structures where prismarine can be found naturally — the other being ocean ruins. Unlike many other generated structures, the Ocean Monument contains no loot chests anywhere within it. Players looking to locate one can obtain an ocean explorer map by trading with an apprentice-level cartographer villager, which marks the nearest monument on the map.
The entire Ocean Monument is constructed from prismarine, prismarine bricks, dark prismarine, and sea lanterns, with a base footprint measuring 58×58 blocks. Twenty-three large pillars extend downward from the structure toward the ocean floor. Inside, the central section features a series of randomly arranged chambers connecting to two lateral wings, while at its core sits a tall treasure chamber containing eight gold blocks encased within dark prismarine. Some monuments also feature sponge rooms, each holding around 30 wet sponges along the ceiling, though these rooms are not guaranteed to appear in every Ocean Monument.
Three elder guardians always inhabit the structure: one positioned atop the central section and one within each side wing. These formidable mobs apply Mining Fatigue III to nearby players, significantly slowing any effort to break through the monument's walls. The surrounding area also serves as the exclusive natural spawn location for ordinary guardians, which continue to appear there indefinitely. No more than one Ocean Monument can generate within any given 512×512 block region of the world.
Ocean Monument FAQ
Quick answers
The fastest way is to use the interactive seed-map finder on this page: enter your world seed and it plots the exact coordinates of every Ocean Monument so you can travel straight there. In-game you can also explore deep ocean biomes, where their large prismarine and sea lantern structures are visible underwater, or use the /locate structure minecraft:monument command in Java Edition.
Ocean Monuments only generate in deep ocean biomes (including deep cold, deep lukewarm, and deep frozen ocean) and need to be surrounded by ocean. In Java Edition they use a placement spread of 32 chunks with a 5-chunk separation, so at most one generates per 512x512 block area and they end up spaced roughly several hundred to a couple thousand blocks apart rather than being truly rare.
Each monument is guarded by many Guardians and 3 Elder Guardians that inflict Mining Fatigue, making it hard to break blocks. The main reward is 8 gold blocks hidden in a chamber behind the elder guardians, plus a chance of a sponge room containing wet sponges; there are no loot chests, but the prismarine, dark prismarine, and sea lanterns are valuable building blocks.
