The underground complex of San Francisco.
Hell is the name of the underground complex beneath San Francisco operated by the Orbs, and specifically a control room. The complex includes Hell, Slavery and Freedom. The control room controls the lava gates and the movements of slaves.
Shafts lead up to Cable Car Barn, Transamerica Pyramid, 555 California Street, Coit Tower and Julius Castle.
The Orbs used human slaves to work in the mining tunnels, but because of the harsh conditions they hired Dr. Noah Goring to engineer stronger mutants. Noah made reptilian Creatures but they were hostile and were trapped in Alcatraz.
The Hell control room.
The existence of the underground, and the importance of Hell control, was known to humans who collaborated with the Orbs, such as Noah Goring, and those against the Orbs, like the Dragon Clan; they made plans to rescue the slaves. Goring sought the help of another Doctor to free the Creatures from Alcatraz, and reach Hell with their help.
Dragon Tad Timov wrote an encrypted note, revealing that "the Julius Castle is the Gateway to Hell", as it includes a forgotten mine shaft.
A slave secretly emerged from the underground to the Cable Car Barn and passed a note to a Dragon, notifying them that the Orbs almost reached Life; the Dragons must help the slaves reach Hell and the slaves will show them Freedom.
The control screen
The Manhunter fell from a balloon to the Julius Castle and dropped on an Orb operator, which was killed. Controlling the gates, he moved the slaves to safe zones, then flooded the Barn, Transamerica Pyramid and Coit Tower with lava, restoring all mutants to their human forms.
The slaves then arrived to the control room and brought the Manhunter to Freedom, and boarded him to a drilling machine.