If you want "natural" it really depends on where you are. The big chunk in the back left though reminds me of hiking on the Appalachian Trail on the east coast of the US. Generally if you see any rocks to mention, they're a big jutting one like that that sort of lean together and hold eachother up. I was looking for some pictures online to help you see what I have in my head, but apparently nobody has taken pictures of what I remember about it...