I remember a Descent PVP level that was a big room with a corridor that came off of one end and went to the other by looping back through the main room but was

I remember a Descent PVP level that was a big room with a corridor that came off of one end and went to the other by looping back through the main room but was not visible inside of the main room. Was a bit of a mindbender in a game that already stretched the players spatial awareness.