Astral Sea

The Astral Sea is all that is known of the Universe. It is bound on all sides by what is refered to as the Far Realm The realm includes many in known and unknown planes of existence, these are where living creatures typically reside. Here are some of the most famous:
Atoria
Celestia
Sunken Isles
Elemental Chaos
Deserts of Arak
Abyss
Nine Hells
Realm of Yonfir
City of Stone
Mechanius