Publisher's blurb: The darkness hides many secrets... ...not all of them want to be found. This set of 12 double-sided terrain cards (plus bonus terrain inside the covers) presents a sprawling cave system rich with subterranean features on one side, while vacant of specific details on the other. Meanwhile, a sheet of extra terrain elements is included for you to cut out to further customize the cavernscape. Mix and match the tiles to create your own tunnel system, or use the cover as a guide. Highlights of this set include the Bone Heap, Crystal Mines, and Sunlit Grotto, just to name a few! Each card measures 5 by 8 inches, and is printed on thick glossy cover stock. The complete set is gathered in a clear resealable envelope for safe and easy transportation.