Neil Oliver is massively annoying and there was a bucketload of conjecture going on there (bloody archaeologists and their assumptions that
absolutely everything must be 'ritual') but it's a fascinating site. I have been there some years before this was known about and I'm not buying their 'journey from the land of the living to the land of the dead' thing, chiefly because Maes Howe (the chambered tomb) is at what he said was the end of the land of the living, the other side of the Stones of Stenness. The whole area's worth a visit, the Ring of Brodgar is very impressive and quite fascinating on a number of levels, the stones themselves have loads of old graffitti on them saying things like 'Magnus Drever was here 1798'