From the introduction:
It's a good plane to begin a tour, cutter, for it's located bang at the centre of the Outer Planes -- a fact which nobody disputes. It borders all the other planes of the Great Ring, touches the Astral, and, it would seem, has Sigil, the City of Doors floating above its heart. If you choose believe the screed, that is.
More is known about the Outlands than many other planes put together, but there are also a great many mysteries to be encountered here. Not least is the Infinite Spire itself, a tapering pillar of dark rock that rises from the flat plains of the Outlands both suddenly and with eyewatering proportions.
The plane itself can be divided into three portions: The Spire, the Gate Towns, and the Hinterlands. The first of these applies to the vast area (called "the Disc" by some locals) radiating out from the Spire. It's here that staunchly neutral communities make their kips, many powers who choose not to choose radical beliefs dwell, and the mysterious grey race of the Outlands hold sway. It's also the largest magic-dead area in the Multiverse, for the Spire apparently draws magic into itself. The closer you are to the Spire, the more magic is affected. This effect weakens until magical powers behave themselves in the second part of the plane...
Clinging to the edges of the Disc are Gate Towns, burgs that perch on the precipice of belief between neutrality and some other philosophy. There's one for each of the Outer Planes, (that's sixteen in all, berk), and all have permanent gates to their respective planes within their walls.
Beyond the ring of gate towns lie the untold mysteries of the Hinterlands. Nobody really knows what they contain, for they have a nasty habit of never being the same twice. Thing is, it's not the churning chaos of Limbo, or the ever-moving revolving discs of Mechanus; the landscape appears perfectly normal. You could walk for years and never see the same thing twice, they say. But turn around, and you're back where you started again. Travellers have told tales of waking in a different place to where they fell asleep, or of cities there that change shape and location hourly. But they also tell of lost civilisations and uncountable riches. Maybe that's why people go there...