The Pontypool and Blaenavon Railway is a 2-mile volunteer-run heritage railway in South Wales, running trains between a halt platform opposite the Whistle Inn public house southwards to the town of Blaenavon via a two-platform station at the site of former colliery furnace of the Big Pit National Coal Museum. Its the highest preserved railway line in Wales if not the UK and also uniquely having the only standard-gauge rail-over-rail bridge within preservation.