Survival Difficulty: Class 3. Unsafe, Unsecure, Low Entity Count.

This is basically a hallway with no end. Each room has a 25% chance of containing at least one random entity from any level. There is locks on every door, but they are all open.

Entrances

Going through the exit in level ! has a 1% chance of leading you here.

Going through a certain building in level 94.

Going through a long hall in level 0.

Exits

Going through a door with an exit sign will lead you to the frontrooms.

Noclipping on a orange part of the hallway will lead you to level fun.

Noclipping through a green part will lead you to level 1820 (https://gamejolt.com/p/level-1820-green-hallways-qhssganv).