Dis

Dis is a location in Hell.

Background
Dis is described in Dante Aligheiri's The Divine Comedy as a walled city at the base of Hell that encompasses the sixth through ninth circles of punishment for sinners (heresy, violence, fraud and treachery).

Doom
E3M8: Dis is the final level of Inferno, the third Episode of the original Doom.

The Art of Doom Eternal
Background for the "Spire City of Dis" appears in the companion book The Art of Doom Eternal, where it is described as a city built on the ruins of "Babel", and that it makes up one of the inner circles of hell (it is unclear if this refers to the collapsed tower or a city) ruled over by an Archdemon called Erebus. Thus far, no direct reference to it has appeared in the games.

Behind the scenes
Nekravol, the City of the Damned and Spire City of Dis] may be intended to be the same location.