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.

Yet the appeal of this line was such that, over a span of some thirty years, volunteer workers young and old, from all walks of life, banded together to dig the railway out of oblivion and hew a new line through the mountains to by-pass that man-made lake. Other railways, and canals, have been rescued since; but the scale and effort of the Ffestiniog story remains quite unmatched anywhere else.

This, the first of two programmes, brings to the screen a number of those who began the transformation to the thriving scene of today. Related by those who were there and made it happen, the story is backed by much previously unpublished archive film, and rounded out with some splendid contemporary scenes of this unique line.