I have just added this to the map of places to fly your drone at Drone Scene:
Big Pit National Coal Museum is an industrial heritage museum in Blaenavon, Torfaen, Wales. A working coal mine from 1880 to 1980, it was opened to the public in 1983 as a charitable trust.
The site is dedicated to operational preservation of the Welsh heritage of coal mining, which took place during the Industrial Revolution.
Located adjacent to the preserved Pontypool and Blaenavon Railway, Big Pit is part of the Blaenavon Industrial Landscape, and a World Heritage Site,
The preserved steam railway is also worth a drone visit but wasn’t running the day I visited
The originator declared that this location was not inside a Flight Restriction Zone at the time of being flown on 19/05/2025. It remains the responsibility of any pilot to check for any changes before flying at the same location. Landowner permission may be required before taking off.