Also known as Wormskull.

1--+--+--+--+--+--+--+--+
                        |
         +--+--+--+--+  +
                     |  |
            +-o+--+-o+--+--+
                     |      \
         +-o+--+--+--+       \
                              v
                  +--+--+--+--+--+--+--+--+
                  |  |     |  |  |  |  |  |
                  +  +x-+  +--+  +  +  +--+
                  |           |           |
                  +x-+--+  +--+        +--+
                  |     |     |           |
                  +--+  +     +x-+--+--+  +
                  |     |     |     |  |  |
                  |     |     |  +  +  |  |
                  +->+  +  +--+  ^  x  |  +
                  |     |     |  |  |  +  |
                  |     |     |  x  v  |  |
                  +--+  +  +--+  +  +  |  +
                  |     |     |  |     |  |
                  +x-+--+     +  +--+--+  +
                  |           |           |
                  +  +     +  +--+  +  +--+
                  |  |     |  |     |     |
                  +--+--+--+--+--+--+--+--+

1 = Thalos {10-25}

Key to Mystic Adventure ASCII Maps