a.k.a. The Elemental Plane of Air, a plane marked by nothing but various densities of atmosphere. There are not many places to stand, save on the floating villages of the aaracockra.
a.k.a. The Elemental Plane of Water, a world-sized ocean, this plane's only solid land is in special environments deep below the water, or the massive ice-floes that are constantly shifting about the plane.
a.k.a. The Elemental Plane of Earth, this arid land is naught but various forms of rock all pushing up against each other for supremacy. The land itself is as stubborn as it's denizens.
Also known as the Elemental Plane of Fire, this land is home to all manner of heat-producing/resistant creatures.