Sigil is located atop the Spire in the Outlands. It has the shape of a torus; the city itself is located on the inner surface of the ring. There is no sky, simply an all-pervasive light that waxes and wanes to create day and night. Sigil cannot be entered or exited save via portals; although this makes it quite safe from any would-be invader, it also makes it a prison of sorts for those not possessing a portal key. Thus, sometimes Sigil is called "The Cage". Though Sigil is pseudo-geographically located "at the center of the planes" (where it is positioned atop the infinitely tall Spire), scholars argue that this is impossible since the planes are infinite in all dimensions, and therefore there can never truly be a center to any of them, let alone all of them; thus, Sigil is of no special importance. Curiously, from the Outlands one can see Sigil atop the supposedly infinite Spire.
The theory is that Sigil contains innumerable portals that can lead to anywhere in the Multiverse: any bounded opening (a doorway, an arch, a barrel hoop, a picture frame) could possibly be a portal to another plane, or to another point in Sigil itself. Thus, the city is a paradox: it touches all planes at once, yet ultimately belongs to none; from these characteristics it draws its other name: "The City of Doors".
Sigil's leader and neutrality
The ruler of Sigil is the mysterious Lady of Pain. The Lady is sometimes seen in Sigil as a floating, robed Lady with a face bearing a mantle of blades. The Lady does not concern herself with the laws of the city; she typically only interferes when something threatens the stability of Sigil itself. However, she is an entity of inscrutable motives, and often those who cross her path, even accidentally, are flayed to death or teleported to her hidden Mazes, lost forever. It is widely believed that she never speaks, although some unconfirmed (and, most would argue, highly questionable) rumours to the contrary do exist.
Sigil is, theoretically, a completely neutral ground: no wars are waged there and no armies pass through. Furthermore, no powers (such as deities) are allowed to enter into Sigil; the Lady has barred them from the Cage, but some disguised avatars have made it in and been promptly dispatched by the Lady. It is also of great interest to them, as they could use Sigil to send their worshipers anywhere, and it is at the center of the Outer Planes. Aoskar lived in Sigil for a significantly long time before he was destroyed by the Lady, however. Sigil is hardly peaceful; with such a condensed population, consisting of everything from angelic devas to demonic glabrezu, violence is common, usually befalling the foolhardy, the incautious, or the poor. Most natives of Sigil ("Cagers") are quite jaded as a result of living there.
People coming to Sigil from the Prime Material Plane are often treated as clueless inferiors by the planar elitists who dwell there. They are thus widely referred to as the "Clueless", or more charitably, as "Primes".
Sigil is divided into six districts, called wards:
- The Hive Ward, the slum and the ghetto, home to the poor, the rogues, and the unwanted dregs of the city.
- The Lower Ward, an industrial district, clogged up with the smoke from the foundries and from the portals to the Lower Planes.
- The Clerk's Ward, an affluent district, home to most of the city's lower-rung bureaucrats and middlemen.
- The Market and Guildhall Wards are the home to the traders, craftsmen, artisans, guild members and other members of the middle class.
- The Lady's Ward, the richest and most exclusive section of the city, is home to the elites of society and of its government, though not the Lady herself.