1) what criteria need to be met to class an obviously natural feature as a genuine TMA prehistoric ritualistic site? E.g Sacred Hill, rock feature etc.
2) what other examples are there out there, aside from Capel Garmon and Bryn Celli Ddu?
A full house and a very good speaker. Bob Trubshaw talked a bit about how the concept of 'nature', 'countryside' and 'landscape' are relatively modern and we have an idealised view of nature. Quite hard to sum up in a few words so I bought his book which he was selling at a greatly reduced price "Sacred Places - Prehistory and Popular Imagination" (ISBN 1 872883 67 2)
In his talk the speaker looked at some of the places we consider sacred - mountain tops, caves, groves, sources of water and came to the possibility that sacred can sometimes equate with terrifying. He also mentioned altitude sickness which causes some mountaineers to experience visions. The book looks like a good read.