Among the world's narrow gauge railways, the thirteen-mile long Ffestiniog in North Wales stands supreme. Its history, engineering, locomotives, carriages, all in its magnificent mountain setting, together make this one of the country's top tourist destinations.

Well over a century ago, engineers from around the globe came to North Wales to study how British ingenuity was bringing trainloads of slate from the rugged mountains of Snowdonia, to serve the building trade worldwide. Yet between those great years and today lay another age - an age of bankruptcy, rack-and-ruin and bramble-choked desolation. Worst of all, nearly two miles of track vanished under a man-made lake.

Related by those who were there and made it happen, the story is backed by much previously unpublished archive film, and rounded out with some splendid contemporary scenes of this unique line.

BONUS FOOTAGE! FFESTINIOG INTERACTIVE (30MINS)

In a fascinating experiment the Ffestiniog Railway invites "would be" volunteers to join members of their operational team for a day of work experience. Join the Guard, the Signalman and Driver in this unique behind-the-scenes bonus feature.