Elemental Plane of Fire
The Elemental Plane of Fire is one of the basic building blocks of the cosmos. It takes the form of an infinite expanse of fire. It is inhabited by fire elementals, and fire elemental forms of mundane burrowing creatures.
The City of Brass, home of genies, is located on the elemental plane of fire.
Where the elemental plane of fire touches the Elemental Plane of Earth it creates the Paraelemental Plane of Magma. Where the elemental plane of fire touches the Elemental Plane of Air it creates the Paraelemental Plane of Smoke. Where the elemental plane of fire touches the Positive Energy Plane it creates the Quasielemental Plane of Radiance. Where the elemental plane of fire touches the Negative Energy Plane it creates the Quasielemental Plane of Ash.
Dark Sun
The paraelements are arranged differently in Dark Sun: Smoke is replaced with sun. In addition, the positive and negative energy planes don't exist, so there are no quasielemental planes.