Sandstone Mine Tunnel
=====================

+-- Level +1 ----------------------------+
|                                     >  |
|                                    *   |
|                                   /    |
|                                  /     |
|                                 %      |
|                                 v      |
|                                        |
+----------------------------------------+

+-- Ground level ------------------------+
|                                        |
|         %                              |
|        /v                              |
|       /                                |
|      *                                 |
|       \                                |
|        \                               |
|         *                              |
|         |                              |
|         |                              |
|         *                              |
|          \                             |
|           \                            |
|            *                           |
|           /                            |
|          /                             |
|         *                              |
|        / \                             |
|       /   \                            |
|      *     *                           |
|     /       \                          |
|    /         \                         |
|   *           *--%                     |
|   |              v                     |
|   |                                    |
|   *                                    |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                        *               |
|                        |               |
|                        |               |
|                        *     *         |
|                       / \   / \        |
|                      /   \ /   \^      |
|                     *     *     %      |
|                    /             \     |
|                   /               \    |
|                  *                 *   |
|                 / \                    |
|                /   \                   |
|               *     *                  |
|              /       \                 |
|             /         \                |
|            %           *               |
|            v            \              |
|                          \             |
|                           *            |
|                                        |
+----------------------------------------+

+-- Level -1 ----------------------------+
|                                        |
|      *                                 |
|     / \                                |
|    /   \                               |
|   *     *#-M                           |
|    \                                   |
|     \                                  |
|      *                                 |
|      |                                 |
|      |                                 |
|      *                                 |
|     / \                                |
|    /   \^                              |
|   *     %                              |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                                        |
|                  ^                     |
|                  %                     |
|                 /                      |
|                /                       |
|               *                        |
|               |                        |
|               |                        |
|               *                        |
|              / \                       |
|             /   \                      |
|            *     *                     |
|           /      |                     |
|          /       |                     |
|         *        *                     |
|        /          \                    |
|       /            \                   |
|      *              *                  |
|                      \                 |
|                       \                |
|                        *               |
|                       /                |
|                      /                 |
|               *     *                  |
|              ? \   /                   |
|            ^/   \ /                    |
|            %     *                     |
|                                        |
+----------------------------------------+