Hmm... hmh.

Castle1, Castle1N, Carrot1. Carrot1N, Labrat1, Labrat2, Labrat3, Colon1 & 2, Psych1 & 2, Beach1 & 2, Diam1, Diam3 (and possibly Diamsecr), and so on. Further levels are named Tube, Medivo, Jung, Hell and (-)(-)(-)(-), all of which have both 1 and 2 by the rest of filename.