It's a carving but of what - nobody will agree. Fortunately it's not in a tilled field otherwise 'ploughshare scar' would be the undoubted verdict. Although it's a circular argument - it looks like this one ( http://www.themodernantiquarian.com/post/38844 ). I'm pretty sure that one's been carved and is not a flaw in the rock. Not far from Cumbria.