Looking back at the hill, you’ll see why I recommended taking that detour to the right; the well-worn way coming down is so steep it requires rock climbing skills. And what a dramatically sudden end to those slopes which are indeed like the plates on the back of a gigantic stegosaurus.
From our viewpoint on the flat valley floor, with a little imagination, it feels like we could be standing on a sea bed, looking up at a coral reef. Well, around 350 million years ago, during the Carboniferous period that would have been precisely where we were. During this period much of Britain was covered by warm, tropical seas as the part of the Earth’s crust that we now know as Europe was actually located very near to the Equator.
The term for these limestone hills is reef knolls. They were formed on the ancient sea bed as layers of tiny dead sea creatures, such as early molluscs and sponges, built up over millions of years to form limestone mounds.