The DungeonMorph Dice Explorer Set includes 30 designs related to kill zones (traps), learned areas (libraries, mage's sanctums, etc.), prisons, tombs and unusual dungeon areas. The font, cards, and battlemats feature all 90 designs, not just the 30 "Explorer Set" designs.
While each die features designs with one of these concepts in mind, each die also includes a couple of fairly generic sides for general use. Even the designs with a specific purpose can be reused by making a small change such as switching barred doors to regular doors.