+-- Ground level -----------------------------------------------------------------+
| |
| * |
| | |
| | |
| *--* * |
| / \ / |
| / \ / |
| * * |
| \ \ |
| \ \ |
| * *--* |
| \ |
| \ |
| * |
| \ |
| \ |
| * |
| \ |
| \ |
| * |
| \ |
| \ |
| *--* * |
| / \ / |
| / \ / |
| * * * |
| / \ / |
| / \ / |
| * * *--* |
| / \ / |
| / \ / |
| * *--* * |
| / \ / |
| / \ / |
| * * * * * |
| / | / \ / |
| < / | / \ / |
| * * * * * * |
| \ \ / / \ \ | |
| \ \ / / \ \ | |
| * * * * * * |
| / \ / \ | / |
| / \ / \ | / |
| * *--* * * * |
| | / | | | |
| | / | | | |
| * * M--* * * * |
| \ \ \ / / / \ |
| \ \ \ / / / \ |
| * * * * * * |
| \ \ \ / / \ |
| \ \ \ / / \ |
| * * * * * |
| \ \ | \ |
| \ \ | \ |
| * * *--* *--* |
| \ / \ / | \ |
| \ / \ / | \ |
| *--* *--* * * * * |
| / \ / \ \ / \ |
| / \ / \ \ / \ |
| *--* * * * * * |
| v \ / |
| \ / |
| * |
| \ |
| \ |
| * |
| \ |
| \ |
| * * |
| \ / |
| \ / |
| *--* |
| / |
| / |
| * |
| \ |
| \ |
| * |
| |
+---------------------------------------------------------------------------------+