The Big Pit: National Coal Museum (Welsh: Pwll Mawr: Amgueddfa Lofaol Genedlaethol) is a museum in Blaenavon in Wales, which is dedicated to the Welsh heritage of coal mining which took place at the town during the Industrial revolution. Big Pit was a working coal mine, adjacent to the preserved Pontypool and Blaenavon Railway. The mine closed in 1980 and reopened for visitors in 1983. Today it is preserved for visitors under the auspices of the National Museum Wales. Big Pit National Coal Museum is an Anchor Point of ERIH, The European Route of Industrial Heritage. It is located close to Blaenavon, in Torfaen, which is a World Heritage Site.