The Dismal Caverns

The Dismal Caverns is a great mass of rock perforated by caverns, chasms, and tunnels of all size. It has no sky and no light except for that given off by luminous fungi and molten lava flows.

To denizens of Tiriande, the Dismal Caverns are known best as home of Ghaunadaur, the god of abominations. A common conspiracy theory is that the Dismal Caverns and the Dungeonscape are, in fact, one and the same, a belief supported by the great similarities between the two.