That, in a quiet way, is precisely the point. A feature marked on the 1932 edition of the Ordnance Survey six-inch map, indicated by hachuring, the cartographic convention used to suggest a small excavation or depression in the terrain, had left no visible trace whatsoever by the time anyone went to look for it in 1983. The best guess, based on the map evidence alone, is that it was once a small sand or gravel pit, the kind of modest working that would have been dug to supply local building or road-laying needs and then quietly abandoned and grassed over.