Thomara

The Crypts of Thomara are the remains of Thomara, a subterranean dwarven city built early in the Age of Arcanum around a vein of precious metal ore by the Thomara clan. Per rumor, the city was deeply xenophobic and greedy, and eventually fell to cannibalism before its eventual collapse, long before the Calamity.

Scanlan revealed that the city itself was built inside a fallen titan, which Vecna resurrected to carry Thar Amphala to Vasselheim.