The Outlands
From Ardrana
The Outlands are what the Clueless refer to as the Plane of Concordant Opposition - a mouthful, to say the least. The Clueless figure that, being a plane of perfect neutrality, the Outlands have got to be the most boring place around. It's obvious they haven't spent time there, and they certainly haven't had to cool their heels in the Astral Plane for too long - now that's boring! Sure, the Outlands don't have the burning pits of Baator, the howling madness of Pandemonium, or even the glowing mountain of Mount Celestia. The Land's a little short on big, spectacular landscapes, but it ain't boring, berk.
It's because the plane's neutral that the place is so popular. Anyone with the means can come here -- that's one of the properties of the plane. On most of the Great Ring, a power can't enter a plane that's not its home, but on the Outlands any power can come and go as it wants. That doesn't mean it can do anything it wants, though. Visiting powers respect the realms of those deities native to the Outlands, and they usually can't enter them without permission. Even petitioners from other planes can come here, though most of them are from the Upper Planes (the guards of the Lower Planes don't like their prizes getting loose).
Sigil stands at the very heart of the plane, balanced on a spire that disappears into nothingness above. This is important: There's no way to walk from the Outlands, or anywhere else for that matter, into Sigil. The Cage can be reached ONLY through the many doors that open onto its streets.
The realms of the Outlands lie mostly along the outer edges of the plane, close to portals that lead to the Great Ring. There are 13 known realms and there's rumors of more, though no blood's ever found them. Most of these realms are the domains of single powers, but a few are home to several related powers. Each realm adopts the character of its ruling power or powers.
Note: The Outlands originally appeared in the Planescape AD&D campaign setting from TSR. Its use here is for the purposes of providing context for the campaign only.