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