Corna

During the Aberrant War, many settlements found allies in beings of power, like dragons or aasimar. Corna found no such ally, their calls for help went unanswered. They retreated into their mines and the invaders followed, but none returned from those depths. The city is a ghost town, the mines remain untouched, though not for lack of trying on the part of adventurers. The only people to have returned did not venture far, but some have reported wails coming from the depths.