Tower of Lies is a single hell-themed map for Doom II where you start in the bowels of Hell and scale your way up a tower and to salvation — or so you hope. It’s an experiment in making the player feel as though he or she is going up and up the floors of the tower without actually using 3D floors. Instead, it’s all done with teleporters and visual tricks.
General consensus is that the experiment didn’t work, but that it’s an atmospheric map (largely thanks to Mark Klem’s “Simple Solutions”) with some cool visuals and fun set-piece moments. I’d say I pretty much agree with that assessment — but try it out for yourself and see what you think!