I only mentioned the Winter Solstice because you did. Also it is the most likely one to be celebrated in such a way, purely for farming reasons.

I think Cosgrove was slightly on the barking side, but I wouldn't dismiss him totally. What I would say is that where the shadow fell would obviously depend upon the size of ya stick! As the actress said to the vicar....

Silbury was obviously built for a purpose, and a bloody great purpose at that. So maybe this is it. Hurrah!!