Small Stone Tunnel
==================

+-- Level +1 ------------------------------+
|                           ^              |
|                           %              |
|                           v              |
|                                          |
+------------------------------------------+

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