I have just added this to the map of places to fly your drone at Drone Scene:
Land owner permission requirements unknown.
There's an elevated viewing platform at the nearby StarDisc which provides a good line of sight across the quarry, as well as a narrow public path that crosses the quarry itself with more limited visibility. Would recommend an early morning trip when other visitors aren't around.
The originator declared that this location was not inside a Flight Restriction Zone at the time of being flown on 15/08/2021. It remains the responsibility of any pilot to check for any changes before flying at the same location.