Just reading again the newspaper account of the excavation of the east and west 'entrance mounds'. And it only just struck me the coincidence that when I was researching Orcadian ring enclosures (in connection with Hillhead) it seems like there was always signs of one or (usually) two mounds under each of these. Is this really how the stone circles of Orkney started out, that the standing stones are a comparative afterthought and we have been misled by comparisons with henges elsewhere. Would explain why there are only two here. And the Ring of Bookan becomes fractionally less enigmatic, the huge fosse no longer indicative of a failed/robbed stone circle but its own thing.