The Realm of Atlos
The Nine Hells
The Nine Hells (more formally known as Baator) is a plane of sinister evil and cruelty.
The different types of devils that dwell here obey a strict hierarchical caste-like social structure. Each continually plots to advance their position through treachery and deception. Unlike the demons of The Abyss, the devils are highly organized, with a logical and calculating nature.
The plane itself is composed of nine different layers, or sub-planes, each of which models a differing but no less inhospitable and dreadful environment, including barren plains of ash and rock to frozen wastes of endless ice.