Out here on the Mendips there are four large henges, roughly in a north-south line. The southernmost was partly excavated in the 1960s and they discovered the bank was made of earth, turf and stones, supported both sides by posts and stakes. The funnel-shaped entrance was outlined by posts. They didn’t find anything actually within the henge – no structural features and no little artifacts from the time of its construction: a deliberately ‘clean’ area? A pollen analysis showed that the land was grassy when the henge was being built, rather than it still being surrounded by woodland.
What’s left is probably best appreciated from the air – I saw a local tv programme recently in which they were flying over the area, and the size of the henges was really impressive. (A bit bigger than vulcan’s photographed circle). One would be impressive enough – but why did they need four (or more)? It’s all so very mysterious.