Underground Lake
================

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