Chronicles of Time
The Demon Dimensions are a series of many planes or pocket dimensions that lie in the lower most planes. These Dimensions are very dangerous, and include the Abyss. It is important to note that these planes are not necessarily terrible or evil, however they are ruled by Demons and not Gods.
These planes have wide ranges of environments. Some may be as seemingly normal as the common planes.
The biggest risk to being in a Demon Dimension is death. Those that die within a demon dimension relinquish their spirit or essence to the Demon ruler. Thus, resurrections from death in Demon Dimensions are very rare, and must often be bartered for by the Demon Lord.