Looking at the above photos reminds of a little story. Living in Bromley south London the local club was making a model of HAwkhurst which has an under bridge. To gather details I made several trips to the site of Brastead (Westerham Branch line)station which has an under bridge, as and when required. a 10 minute journey. Making another trip for detail info I turned a corner and every thing was flattened under the foundations of the M25. The appearance of such a vast open space was disturbing rather like being tranported to another planet.