There is a religious and scientific belief/theory that the world is divided into three rings. However, mages all around generally agree that this is more a fact than it is a theory, and priests of various deities have preached the world's cosmology for centuries. There are several different versions or beliefs as to how the known universe is built and put together, though the map (right) is the most commonly known and accepted representation; as determined by several high standing priests and mages both.
The outer ring consists of the High Halls, where the gods reside. The ring beneath the High Halls is known as the Divide; a protective shell and realm of magic weaved long ago by the gods to prevent mortals from reaching the High Halls. Due to its instability built up over the last few thousands of years, it also functions as a crossroad which other worlds might use to travel to Tariel, and thus the other way around as well, though it is seemingly a rare occurrence. Past the Divide, closer to the center, lies the Veil. The Veil is technically part of the Divide, but it sustains a weaker form, making it ideal for Otherworlders and Planeborn to intrude through.
The Divide is also where Celunar and Lucine travel; the sister moons. They circle Tariel as if chasing each other, and while only one moon is ever present on the night sky at any one time, and while they are not so easily distinguishable from one another, it is known that Celunar and Lucine seem to, as it were, take turns on when they show.
Surrounding all of the cosmos is Sol, commonly referred to as the sun. According to some religious texts, Sol is either a greater entity whose power exceeds that of the Creators, or it is the deceased Creator Sol, whose light has engulfed the universe around her. Only theories surround the nature of Sol.
In reference to the Veil, Mages have long used the Veil for various experiments; often dangerous
ones, where they create hidden sanctuaries for themselves in the Veil. But the Veil would most apparently seem to draw the attention of spirits; particularly so of the deceased. Spirits of the dead flock to the Veil, where they await their benefactors or wander endlessly in grief and confusion. The practice of Veil Sanctuaries have since the fall of the Old Imperium decreased significantly, and most Mage Orders outlaw it. Those who venture into the Veil sometimes come across abandoned Sanctuaries, most of which have been abandoned since the days of the Old Imperium.
The inner circle is the Mortal Realm, where, as the name implies, mortals reside. This is the centre of Tariel, where the gods draw most of their power from, and where all energies of the surrounding universe converges to sustain the world's balance. Past these rings lies the Dark Beyond; presumably the rest of the universe, which is also commonly referred to as the Otherworlds. Eight other planets are known to reside in close vicinity to Tariel, though astronomers agree that there are likely more. These Otherworlds are very similar to Tariel in their own rights.
The circles that lie between the Divide and the Mortal Realm are representations of planes or worlds that have either intruded upon Tariel or always existed beside it; having over the many ages become far more accessible to Tarielborn, Planeborn and Otherworlders as the understanding of magic grew. These planes are simply known as the Planeworlds, and while there are currently eight represented planes, experts agree that there are likely many more planes waiting to be discovered.
Additional realms exist within the Mortal Realm itself. Although it is dwarf-made, the Underhalls is generally considered a realm of its own. The Underneaths are just below the Underhalls, where several former Dalh Shavai cities reside and other mostly unknown terrors. Below the Underneaths lies the Underdepths, which is almost completely unexplored and few surfacers have ever gone there. At the very center of the Mortal Realm is the World Core, where the prisons of past Primordial Titans and the fallen Creator turned Archon, Gaerdras, reside; watched over by Black Dragons.