Minecraft wiki entry for Dungeon, associated text: Five dungeons and 2 cave spider spawners close together in a mineshaft, cleared to show all 7 spawners.
A double dungeon, the wall of the first acting as the entrance of the second.
A double dungeon with three chests.
A triple dungeon.
Extremely rare double-decker dungeon.
A dungeon in a dungeon.
Triple Dungeon around the village.