From the file's description: You're in a small manse on the outskirts of reality. Find the way to the exit or die trying.
Another underappreciated 1-map Doom 2 wad in my opinion made in 2003. Map takes place in a trap-filled mansion. This is my favorite among Bluepaladin's maps.
Link to the original wad author's page: Doomwadstation.net
cool beans
This map is nothing special by today's standards but pretty interesting for its time.