The Underworld (Grid Series)

The Underworld (also known as Hell) is the home of Daimons, their independent Demon brothers and the Morlocks, it was supposedly designed in layers and the lowest two hold a large gap that allowed the Flames of Perdition to rise up through. The Underworld is made of Seven Layers with countless floating rocks, sealed with Demonic Magic, that make up alternate Sub-Dimensions. The Underworld is divided into four layers, which Celestials have dubbed "Assiah's Basements", or just "Basements".

The Layers and Locations in Hell
Hara - The Second Layer of the Underworld and Ruled by an unknown Dark Lord, its most notable feature is that on one of its flying rocks is Queen Bansheera's Shadow World where the independent Demons reside and are currently trapped. Hara is actually a Demonic word meaning "Stomach", therefore it is possible that it is ruled by Beelzebub, the Dark Lord of Gluttony. Hinmoku - Little is known about Hinmoku except that is named after the Demon word for "Silence", it is possible that it is ruled by Belphagor, the Dark Lord of Sloth. Shi no mon - Shi No Mon is named after the Demon words for "Gate of death", it has a large gap in its centre that holds the portal known as the "Dark Gate", its ruling Dark Lord is unknown. Shi no Kage no Mon - Shi no Kage no Mon is named after the Demon words for "Gate of the death's shadow", floating over Shi no Kage no mon is the giant portal known as the "Dark Gate". Hametsu Sheol
 * Anagura - Ruled by Lilith and her Husband, this Layer is home of the Lesser Daimons and Morlocks, there was once an entrance from there used by the Morlocks to get to Earth (the Gates of the Underworld) however it is believed that with the fall of the Master the Gates have actually been destroyed with Luther yet having to repair it. Anagura is actually a Demonic word meaning "Storeroom".