A word of caution - a desk based assessment of historic images by people that actually knew the Avebury stones very well suggested the Cove stones might fall, but when they spent a packet on engineering kit and scaffolding and excavated below, the stone giving rise to concern was found to be roughly 7x4.5x1.5m with 3m of it under the ground and estimated at 100 tonnes - one of the largest in Britain and it wasn’t likely going anywhere…