Uppermost of the Nine Hells, a land of ash, flame & war, a frontline in the Blood Wars.
Avernus is a hostile place, the first layer of the Nine Hells, and one of the major battlegrounds of the Blood War. A wasteland of charred, rubble-strewn plains, with mountains and talus-sided foothills breaking up the monotony. Legions of mail-clad devils are on perpetual watch here, always assembling for some new cross-planar Blood War sortie. Blood-red light suffuses the air, and fiery balls flit randomly across the sky, sometimes detonating to terrible effect. Runnels of blood flow in streams across Avernus, finally joining the River Styx. The origin of the blood is uncertain, though the devils claim it comes from Avernus’ mortal victims.
The centre of the Bronze Citadel holds the personal fortress of Bel, a pit fiend of great power who controls Avernus; in addition to being a Lord of the First, Bel is also a general in the Blood War, though not one of the Dark Eight.