Stone Tunnel (2)
================

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

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