From PathfinderWiki

Zvartjan is a series of islands located in Iobaria's Deeprun Crevasse. Rising out of Lake Pirstjoi near where the Myrfrus River leaves the crevasse, it is believed the cyclopes of the Koloran Empire quarried much of their stone from these islands. The local centaur populations fear the place, and the few humans have explored the islands and lived to tell of their findings. The islands themselves are cloaked in thick fog for most of the day, while at night strange screams and howls echo from the islands.1