There are a few, what are laughingly called, landfills around this area...the purpose of a landfill, I thought was to fill a hole in the ground...usually with the excess human detritus that doesn't rot for a thousand years...but there are now new hills formed where no hills existed before or at least not in human memory(one prime example is glaringly obvious on the A24 from Kingsfold into Horsham.....I have a feeling that one such new landscape has covered over two "listed"(on old maps) tumulii near Storrington too...I haven't investigated but I noticed a "new hill" on (or at least perilously close to)the site, whilst driving past quite recently.