Derek Brockway treks from Harlech to Barmouth, stripping down to basics as he crosses a nudist beach in Gwynedd. On this walk along one of Wales' most popular coastlines, Derek also rolls a cheese down the world's steepest hill and learns about the 'Devil in the Shawl' when he visits an old village chapel. Along his journey, he nearly gets caught out on a tidal causeway and meets a team of women who give up their free time to keep the beaches clean and safe for wildlife