Ethereal Plane

The Ethereal Plane was created after The Creation of the Material Planes was completed due to the gods' desires to have a more direct way of observing the Material Plane without interfering. Most notably Sinavāḍu's Archives lies within the Ethereal Plane, ever moving, so he can watch all of history unfold before his eyes. The Ethereal Plane does not have a landscape of its own, instead is it just an invisible plane that lies right on top of the Material Plane but kept from the eyes of most of its denizens. For this reason the Ethereal Plane and the Material Plane have the thinnest planar barrier of any of the planes.