I'll post the first 3 pictures from my trip to Norfolk today and add a couple more tomorrow hopefully. The first picture is of a natural shelter I saw and thought to be noteworthy. Books often talk about how it is more efficient to improve or use an existing shelter rather than make your own from scratch. This one was probably just about shower proof and would have served well to reflect or retain some heat from a fire.
The next 2 pictures are of a man made shelter of a broadly similar design which takes advantage of a tree growing out of a bank. As can be seen from the inside of it it isn't very big but is nice to see and probably quite functional all the same. I'd love to know who built it so I could tell you more about it!