In reply to Doug:
I think that Snell's field was used at the same time as the Biolay, at least we'd heard about it, but it didn't appeal because it was said to be crowded and without shade. The Biolay was actually very pleasant, nice little nooks and crannies with seat sized boulders, trees and such like. There was no water on the site but a tap not far away. Before being a "free" site I think it was a proper one and at the entrance there was a sort of bunk house or hotel that had shut down by the time I started going there, in 69.
We used to hide in the woods when the police came round, but they never seemed all that determined when I was staying there, just going through the motions.