From the North to the South of the Principality, the Welsh railways hold a unique appeal, and in this programme we discover some of the great sights of Welsh steam. On the main lines we see express passenger locomotives running to Anglesea along the north Wales Coast. In the mountains of Snowdonia we visit the great Ffestiniog Railway and the re-born Welsh Highland Railway and witness the pioneering Tal-y-llyn Railway, and BR's last steam outpost at Devil's Bridge. We follow the Welsh Borders, climb to the Big Pit, and travel the South Wales main line. On the borders we go deep into the Forest of Dean and run along the Dee Valley at Llangollen.