Caverns of Thracia. (snip)
Definitely not Tomb of Horrors. The rooms only make sense in a self-contained way, and there are instances where the DM has to think for himself how different situations play out, because the whole thing is designed in a stream of consciousness kind of manner. It's a very challenging dungeon and that's as far as it gets.
mordenkainen's fantastic adventure/maure castle/additional levels of maure castle released in future dungeon magazines.