I know it's a bit of an old chestnut, but does the presence of cup marked stones in souterrains not argue in favour of some kind of ritual activity? Despite my interest in rock art, I've never really looked into the subject of souterrains (or RSCs for that matter).
Does anyone have any idea what percentage of souterrains have marked rocks associated with them. And what about fogous? Anyone ever seen a cup mark at a fogou?