Nine Hells

The Nine Hells is the home plane of the devils. It is a plane of evil and unlike the Abyss is highly organized with a strict caste system.

Iron City of Dis
Dis is the second layer of the Nine Hells. The archdevil who rules over this layer is Dispater, who styles himself with the title of "Iron Duke". At the center of the city is his home: the Iron Tower. The Iron Tower is an impregnable fortress, and the paranoid Dispater has enchanted it so that it is equidistant (the tower is always far off, no matter how close to the city center an individual might try to get). Dispater never leaves the Iron Tower unless directly commanded by Asmodeus. When he does so, he always has at least nine different backup plans and escape routes prepared.