Underdark, The — The world-spanning subterranean realm that underlies all the surface lands. Some sages believe that the Underdark is bottomless — or rather, that it eventually impinges upon and then gives way to the Far Realm.

Shallowtown — a sizeable cavern, with floor area approximately equal to 1.5 football fields, located in the Shallows beneath the southern edge of Lake Sammeister just outside of Kirkilston.