Grand Stair
===========

+-- Ground level --------------+
|    >   <                     |
|   *     *                    |
|    \   /                     |
|     \ /                      |
|      *        *        *     |
|              < \      < #    |
|             >   \        \   |
|            *     *        *  |
|             \   /        /   |
|              \ /        /    |
|               *        *     |
|               ?        |     |
|               |        |     |
|               *        *     |
|                        v     |
|                              |
+------------------------------+