Location from Chainsaw Man by Tatsuki Fujimoto
A pocket dimension created by the Eternity Devil — an infinite loop of a hotel's 8th floor where stairs and elevators always return to the same place. Division 4 was trapped here until Denji chainsawed his way out.
The Eternity Hotel isn't a real hotel — it's a trap. The Eternity Devil converted a hotel's 8th floor into a closed spatial loop where no exit exists. Division 4 discovered the loop gradually: taking stairs up or down always returned to floor 8. The elevator opened onto the same hallway. Time began to distort. The devil offered freedom in exchange for Denji. Instead, Denji dove into its flesh-mass core and chainsawed for three days. The pocket dimension collapsed when the devil died.
An ordinary-looking hotel floor — carpeted hallways, numbered doors, elevator banks, stairwells. Everything looks normal until you realize the stairs loop back to the same floor. The elevator opens onto the same hallway. Windows show nothing. The same floor, forever.
Also known as: Eternity Hotel, The Hotel, 8th Floor, The Infinite Hotel