Derek and the team travel to Snowdonia to walk a section of the Slate Trail, created to promote the former slate-mining communities in the area. The route takes him from Capel Curig, where he has a go at rock climbing, via the stunning Swallow Falls, to picturesque Betws-y-Coed where he is given a lesson in charcoal drawing. Meanwhile Onkar Singh Purewal joins some first-time visitors to the area and history hunter Dr Erin Lloyd Jones searches out relics from a time when the area was at risk of a German invasion. Show less