World War One Bomb Sites

If anyone can answer this question it will probably be someone belonging to this forum. A few years ago now I read in one of the aviation magazines that there still exists, or at that time existed an untouched WWI bomb site in London. If my memory serves me correctly it could be seen from the raised part of the M4 entering London. Further details of the site I cannot remember other that it belonged to an old lady who refused to sell it and that there was some discussion that the site should be preserved as a memorial to the raids that took place on the Uk during the Great War. Does anybody remember this and are there any other similar sites in the UK?

Martin