You noclip backwards in a mill and end up in an infinite 999 Googolplex kilometers long and wide industrial corridor with pipes lining the walls and ceilings, and vents connected to the pipes, with gray monotone lights everywhere on the ceiling.
You noclip backwards in a mill and find yourself in an infinite 999 googolplex kilometers long industrial gray monotone concrete hallway with pipes lining the ceiling and white matrix lights on the walls, with monotone red brick pillars scattered everywhere.