This is a scenic abandoned qranite quarry near Princetown, about a mile and a half off the main road to Tavistock. Stone from here was, amongst other things, used to build Nelson's Column in London. A popular destination now for photographers and anyone else who can walk that distance OK along a level track, but you need to be able navigate the very rough path into the entrance to the flooded quarry itself, and the rough terrain of the unflooded northern part. So if you're not 'young', take a hiking pole or similar. If you take children with you, beware that there are cliffs and other sudden drops. Take a real wide angle lens with you if you can, and get some shots from around the top and of the ruined buildings. Give it a couple of hours at least.