One needs to be a bit careful about making too much of piles of stones. When the land was organised for "modern" agriculture in the, I think, 1700's onwards, thousands of tons of rocks that were strewn about by glaciers were cleared and dumped in piles in and around the fields. We still do it today. Only a few years ago we had some boffin get really excited at a pile of stone and was convinced that it might well be an ancient Broch. He was not very happy when one of my sons told him that it was just a pile of stones and boulders that we had cleared from a field a few years before. Ho hum! Great pictures nonetheless.