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