Sean Fletcher is in the stunning setting of Snowdonia, an area celebrating 70 years since its designation as a National Park, to discover how faith has been put into practice by local Christians past and present. He visits the 5th-century coastal church of St Tanwg to hear about the roots of Christianity in Snowdonia and discovers how the arrival of Celtic missionaries in north Wales in the 5th and 6th centuries led to an era of Christian influence that became known as the Age of Saints.James Lusted visits the Ffestiniog Railway, the oldest independent railway company in the world, to hear about the role the railway has played in the life and slate-mining history of the local community. We also discover the story of an iconic hotel that stands in the shadow of Mount Snowdon and has been pivotal in the history of mountaineering, most significantly in relation to the successful British expedition to be the first in the world to climb Mount Everest in 1953, led by Sir Edmund Hillary. And Sean meets a volunteer with a local conservation charity devoted to balancing the demands of tourism in the Snowdonia National Park.