Rocky Tunnel
============

+-- Level +3 -------------------------------------------+
|                                                       |
|            %                                          |
|            |v                                         |
|            |^                                         |
|            %                                          |
|                                                       |
+-------------------------------------------------------+

+-- Level +2 -------------------------------------------+
|                                                       |
|            %                                          |
|            |v                                         |
|            |                                          |
|            *                                          |
|            |                                          |
|            |^                                         |
|            %                                          |
|                                                       |
+-------------------------------------------------------+

+-- Level +1 -------------------------------------------+
|                                                       |
|         *--*                                          |
|        /   |                                          |
|       /    |^                                         |
|      *     %                                          |
|      |                                                |
|      |                                                |
|      *                                                |
|      |                                                |
|      |                                                |
|      *                                                |
|     /                                                 |
|    /                                                  |
|   *                                                   |
|    \                                                  |
|     \                                                 |
|      *                                                |
|       \                                               |
|        \                                              |
|         %                                             |
|         v                                             |
|                                                       |
+-------------------------------------------------------+

+-- Ground level ---------------------------------------+
|         ^                                             |
|         %                                             |
|          \                                            |
|           \                                           |
|            *                                          |
|             \                                         |
|              \                                        |
|               *        *     M                        |
|                \       |     |                        |
|                 \      |     |                        |
|                  *--*--*     *     *                  |
|                       / \    |    /                   |
|                      /   \   |   /                    |
|                     *     *--*--*                     |
|                          /   |   \                    |
|                         /    |    \                   |
|                        *     *     *--*               |
|                              |     |   \              |
|                              |     |    \             |
|                              M     *     *--*         |
|                                              \        |
|                                               \       |
|                                                *      |
|                                                 \     |
|                                                  \    |
|                                                   *>  |
|                                                       |
+-------------------------------------------------------+