Big Pit (Welsh: Pwll Mawr) was a coal mine opened in 1880, which today is preserved for visitors under the auspices of the National Museums and Galleries of Wales as the National Mining Museum of Wales.
Big Pit is an Anchor Point of ERIH, The European Route of Industrial Heritage. The museum is located close to the South Wales valley town of Blaenavon, which is a World Heritage Site.
The pit was first worked in 1860, called "Big Pit" because it was the first shaft in Wales large enough to allow two tramways. In the late 1870s the shaft was deepened to 293 feet. By 1908, Big Pit provided employment for 1,122 people, but this number gradually decreased until by 1970 the workforce only numbered 494. It closed on February 2, 1980.
The mine reopened for visitors in 1983. Big Pit is adjacent to the preserved Pontypool and Blaenavon Railway.
As with all national museums in Wales, admittance is free. The site was redeveloped in 2003, with design work from TACP/Brooke Millar Partnership, Powell Dobson Partnership and Haley Sharpe, with Davis Langdon providing cost and project management services. In 2005, it won the prestigious Gulbenkian Prize.
No 'contraband' i.e. matches or lighters or articles with batteries such as electronic watches or cameras are allowed down the shaft. Visitors must surrender these for temporary safekeeping before they enter the cage.
Note: Children must be over one metre tall to go underground