Publisher's blurb: The Open Space with Rocks group of Naked Geomorphs contains 8 tiles, each with open space (S) at all six positions, and islands of rock. Sets A and B are completely interchangeable. Indeed, all tiles of this group are interchangeable. Tile S1B can be replaced with tile S1A or tile S8B without changing the basic structure of your map. Set B has somewhat larger rocky islands than Set A.