These are planes of the Inner Sphere, layered around the material plane, each composed of an element of existence.
“The Plane of Air is an elemental plane of the Inner Sphere, which in metaphysical terms is the...Plane of Air
“The Elemental Plane of Fire is the outermost of the elemental planes, encircling the Plane of...Plane of Fire
“The Elemental Plane of Water is a plane of the Inner Sphere composed almost entirely of fresh...Plane of Water
“The Elemental Plane of Earth is located within the Inner Sphere, between the Plane of Water and...Plane of Earth