About Dungeon (Monster Room)
Use the Dungeon reference to recognize cobblestone rooms with a central mob spawner. Check the listed mobs and notable chest loot, then read the tips before exploring or planning around the spawner.

STRUCTURE LABEL • OVERWORLD
Biomes: Underground everywhere, often opening into caves
Small cobblestone-and-mossy-cobblestone rooms with a spawner in the middle; you usually hear the mobs before you see them while caving.
The mob spawner can be turned into an XP farm — light or water-flood the room instead of breaking the spawner.
Use the Dungeon reference to recognize cobblestone rooms with a central mob spawner. Check the listed mobs and notable chest loot, then read the tips before exploring or planning around the spawner.