What is it?!

Not one image but the aggregation of over 100 that have been put together to create a three dimensional model of the site  and then this snapshot was taken from that model. To get a sense of scale, I can be seen sitting next to a blue coat top right.
Tricia and I discovered this site on 10th February but it was totally overgrown with heather an donly one stone was visible from above. 
Today the 8km walk in and out and two hours spent clearing heather left me quite tired. At least now one get an idea of the structures here but I am not sure it has helped us know what they might be. Quite an odd spot but set in an Iron Age and Norse landscape with the land to the right forming a peninsula.. Suggestions welcomed.
The pub was shut so the reviving shandy had to be partaken of at our house.