Helen Mark follows Snowdonia Marathon and meets some of the people tackling this challenging course. Starting and finishing in Llanberis, the race encircles Wales' highest mountain of Snowdon, and rises to over a thousand feet in places.

Andy John, Bishop of Bangor is taking on the Marathon for the third time, and he describes the sensation from running the course as being lost in the landscape but found in yourself. But he's dreading the twenty-two mile mark when he'll reach the 1200ft climb at Bwlch y Groes or "gap of the cross", before descending back into Llanberis for the finish.

Helen stops at the ten-mile mark to meet Arwyn Owen at Hafod y Llan farm to find out how Hydro-Electric Power is the new cash crop in this rugged environment. She also meets Phil Owen at Llechwedd Caverns to discover how the area became the slate-mining capital of the world. Both Phil's Father and Grandfather worked in the mine, but Phil became a musician and serenades Helen on his ukulele, three hundred feet below the surface.

Helen hands out water and energy gels with volunteers from the Snowdonia Society at the halfway point in Beddgelert and speaks to Margaret Thomas about Esme Kirby, the remarkable woman who set-up the organisation, before returning to Llanberis to greet a weary Andy John as he's crosses the finishing line.