The Black Vault is a Dark Iron bank located inside Blackrock Depths within Shadowforge City. It is accessed through a door situated between the Domicile and the Hall of Crafting. It is initially guarded by Warder Stilgiss and the darkhound Verek. Opening all the twelve coffers inside with Relic Coffer Keys will summon Watchman Doomgrip and four golems, which have to be defeated in order to receive the Heart of the Mountain. A chest will also spawn which contains green and sometimes blue items.