I still can't make my mind up.

I remember one of the stones in the SE inner circle at Avebury that has a mangrove root pattern that looks very CnRish, but on the other hand the 'ring' on Slumpy's stone looks too full-on circular. Slumpy must have stared at a few mangrove root casts in his searches and he's discounted that, and part of me really wants them to be artificial and prehistoric, as it would be nice to have a thing that showed there may be some link between natural holes, as found in sarsen, and CnR style RA such as we get up north. But then just when I'm thinking that, I get cynical again due to the definitely natural linear striations. They seem to be similar in depth/texture etc to the 'ring'.

I'm going to get my fence cushioned so I will be able to sit on it in greater comfort.