Publisher's blurb: The Tunnel Single and Double Deadends group of Naked Geomorphs contains 15 tiles, each with one or two unconnected tunnel entrances (T), and rock (R) at the remaining four or five positions. There are actually twelve different connection patterns; this group contains two tiles for each single deadend pattern, because those are so useful as edge and corner tiles. Sets A and B are completely interchangeable. I.e., tile T165A can be replaced with tile T165B, without changing the basic structure of your map. Set A has narrower tunnels than set B, with lots of one-hex-wide passages, some small to medium galleries, and a fair amount of deadend branching.