Teeth of the World
The Teeth are considered impassable and have not been explored, though much of the region may have been inhabited by Necromancers during the Golden Age of Necromancy. The Feast of Aeons is considered to be in the region.
Because the Teeth are likely impassable, the necromancers may have utilized mapped tunnels through the Duat to connect various outlying villages. Also possible are uncharted passes leading of Arcol Steppe.