About This File
The level is supposed to represent a prison, complete with exercise yard, guard rooms, surveillance alcoves.
Some highlights include invisible stairs, an invisible lift, and a storage room that has one way walls around the entire room.
For best results, you will need to play with monsters. Make sure that you don't have -nomonsters on your command line, and that any DOOM frontend you are using has this button unmarked.
Please send me your feedback so that I can improve and expand on this concept.