Larry and George Lamb explore Britain’s national parks riding their bike. This week, the pair cross the border into Wales, testing themselves against the mountainous peaks of Snowdonia, and then hit the rugged cliffs and pristine beaches of the Pembrokeshire Coast. For Larry, the tour around north Wales is a nostalgic one as he last visited as a teenager, getting his first taste of life outside London. These days, he and George find the contrast with the capital as stark as ever.