Black Sea
=========

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

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

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

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

+-- Level -4 ----------------------------------------+
|                                             ^      |
|                                             %--*>  |
|                                                    |
+----------------------------------------------------+