A world that was damaged during its formation, rendering it unable to form a proper celestial sphere within the Outer Darkness.
As the Pit is a plane rather than a sphere, the cardinal directions are determined by the placement of four great rivers. Each of these great rivers starts from a cold void at the Pit’s edges and then flows inwards towards the Pit’s center.
A series of terrible cataclysms have left the Pit deeply scarred. At the beginning of the current Age, the ichor of slain gods spilled into the seas, turning them poisonous and cursed. The waters of these seas were so cold they boiled flesh from bone. Over time, the waters have begun to return to normal but there are still many regions where swimming is certain death.
Oddly enough, sanctuary can be found on the lands situated around the severed body parts of the Proteans. The water in these places is purified by the lingering divinity of these body parts, which seems to counteract the divine rage and sorrow that stained the water in the first place.
The Pit has two kind of moons.
The misty moons are sandy masses of congealed smoke and singing mist. They form as mist rises from the Pit’s center and congeals within the air. They are short lived things, gradually crumbling away as time passes.
The true moons were formed at the dawn of the current Age and seem to be made of stone, metal, and bone. Many of them are anchored to the Pit with great black chains several miles long.