Aether

The Aether is a plane of mists that interprenetrates the Inner Planes and acts as both a barrier and a passage between Aiaos, the Primal Wild, the Grim Plain and the Elemental Planes. It is also possible to move thorugh the borders of the Aether and so bypass obstacles in another realm. There are only a few creatures native to the Aether, most of which are harmless. The few aetherial predators stalk the borders and prey on the material.
Things in the Aether lack physical form, existing as semi-coherent energy. This prevents them interacting with the material world, save through great effort, but also allows them to pass through physical barriers.

Type

Dimensional plane