The Shifting Desert

The Shifting Desert is an entirely new plane of existence.  It was not created by any known deity - instead it seemed to materialize in the void left behind by Gehenna when it was exiled from The multiverse at the end of The Age of Coalescence.  Indeed - even existing portals, spells, and other effects which originally brought creatures to Gehenna now direct them to The Shifting Desert instead. 
Information on this plane is still scarce, but it seems to be populated by strange beings composed of alien beings.  Creatures composed of goop, smoke, or even plant life roam the sands, constantly reconfiguring their own bodies to suit the task at hand.

Type

Dimensional plane

Location under

The multiverse