Oh and if you lot like adventures, I know of a hole in Merstham near Caterham that's in the hedge row of a field. It goes down twenty feet. The diameter of the hole is about 3 feet round just enough for a body to tightly squeeze down. Then at the bottom there's a sidewards hole like the entrance to a rabbit den. Pulling yourself down through it, and passing the point of no return, you have to shuffle along on your back some ways. Then after all that misery, you come out in an underground cavern. Water forming lakes, and rocks everywhere. It led off past the first lake and into the distance. I never went and turned around fast. Was glad to be back up in the field when I got there.