Planes of Chaos
There is the Elemental Chaos which is closer to the Material Plane and then there are the Planes of Chaos which tend to be the more Chaotic of Planes of Existence.
I really do try to make most of this original, but since Forgotten Realms is an integral part of the world I can't help if anything is used without formal permission, but is still "fair use" as I am just using this for my private games.