Thank-you David, that's fascinating. I'd often wondered if the hole was for observation, possibly for the moon or certain stars as we (and no doubt the ancients) are all too aware that the sun can't be directly observed. That is a great discovery!
Interesting also that you mention shadows, that's an area very much under-observed I think, most people look at the stones and structures themselves, not at the shapes and directions they cast (apart from in a Meaden/fertility aspect)
I'll continue to read your findings with interest, you're doing something I'd love to be able to do myself.
Something is not right. This message is just to keep things from messing up down the road