The Underdark is the vast network of massive underground caverns and tunnels underneath the realm that serve as home to some of the most dangerous creatures in the Realm.
- World Above
- The surface area of The Realm. The name those who live in the Underdark give the surface.
- The first three miles below the surface.
- Located three to five miles below the surface, this layer was where most of the Underdark cities are located.
- Ten miles or more below the surface, the Lowerdark is where even those who call the Underdark home refuse to go.
- Anraki Empire