The hill of Thorpe Cloud looks conical from certain perspectives -- and, as you discover as you walk around it, actually is conical from all of them. This is because it is a former reef knoll: a pile of calcareous material which accumulated on the bed of a warm shallow sea some 350 million years ago. As it grew, the reef knoll's cavities were occupied by communities of organisms; they left the pockets of fossils that can (allegedly) still be found today.

Unfortunately, there wasn't time to climb to the top of the hill, which was a pity: the views would have been spectacular. But here's a small selection of photographs of the hill itself (and the sheep which graze it).