Dungeon Mastery: Building realistic maps

An exploration of the wilderness on Googlemaps and we find this odd hexagon shape on the edge of a river positioned near a 'natural weir'.
The hexagon with a giant tree is a hundred feet in diameter.

A pen drawing of what can be seen is easy enough. Its not totally accurate.

Then we just colour it with appropriate terrain colours generating a reasonable wilderness map providing us with the ancient ruins of some hexagonal based fortress or temple on a river. An ancient tree grows through the ruined structure hidden beneath its branches. The weir could do with some repair,  There is an access bridge about ten feet wide and twenty feet long crossing the moat.


Enjoy...