Delmarin
The caves of Delmarin were located deep beneath the halls of Blackrock. They were inhabited by the Dyissans, a race of half-snake, half-human hybrids led by Queen Taralis, who was assisted by Sanass, the Chosen. The Dyissans greatly disliked outsiders and attacked if provoked. In a stale living area in the upper elevations of Delmarin, the Dwarf Brignal Rockgrinder had made a home for himself, while Dinar Fleetfoot tamed large ant mounts to be sold in a nearby stable and Filnan Agan'adin brewed stout ale.
The caves of Delmarin were wiped out of existence by Pazuzu's Vigil cult and the brambles of a corrupted Yggdrasil in 922 AF. After a bloody battle, Yggdrasil relinquished its touch upon the Prime Material, taking with it the foundations that anchored the caves to reality.