Jothvauk

Jothvauk is a subterranean citadel surrounded by a fiery lake. In 141 GE it became a refuge for several hundred fire giants wanted nothing to do with the angel and demon war coming their way. They left the mining pits of Vith Ruus following old lava tubes to the rocky isles of Onairions Pool. Across the isles they built great citadels. In the Hoof Front (215 GE - 230 GE), the citadels of Jothvauk were attacked many times, and sometimes served as refuge for Covenant forces.

The isles were like the teeth of a great dragon, each a blockhouse bristling with defenses. The center-piece was Jothvauk, a place of walls and towers, castles within castles, certain defeat. We will lose less on a direct attack against Oratu Iru.

- from the Orcus chapter of the book - "Hoof Front War Decisions"

After the Demon Spawn War (89 GE - 269 GE), Jothvauk's population expanded to include Fyrreid, Salamander, and other fiery brutes.