John Elwyn Kimber: Not the best wild swim on Dartmoor, but better than it sounds and it adds to the amenities, especially if you want still, cold water as a change from all those torrential plunge pools. Dartmoor doesn't really do Welsh Llynnau, but this is more like it than the moorland ponds.
The pool is surprisingly grand and scenic by quarry-pool standards, and is well-known as a good place for a dip on a hot day if you're a local rambler or climber.
Anthony Golding-Cook: Take B3357 from Tavistock towards Two Bridges. Just before the right turn to Princetown park at the entrance to Yellowmead Farm. Follow the track past the farm to the quarry. Sheltered, secluded flooded quarry, easily deep enough for a good swim.
Be mindful of granite boulders in the shallows