World's Largest Dungeon
This room is actually a pair of rooms, a western room and an eastern room.
The western room contained a number of humanoid skeletons chained to the walls. There was a wide variety of skeleton types, including a variety of humans, elves, dwarves, gnomes and the like, as well as a number of humanoid skeletons more difficult to identify.
The eastern room also contained a number of bodies, but these were of more exotic creatures, and several of them weren’t skeletal. There were, among other things, the desiccated husk of a giant spider and a bear which seemed magically preserved. At Kremlin’s request, Thokk severed one of the bear’s arms. The insides of the bear were a black, viscous fluid which was congealed into a sort of pudding.
Both rooms had an eerie feeling about them.
According to The Curator, these rooms are holdovers from a Duergar Empire which once reigned in this place.