Weatherman Derek Brockway visits Rhondda Cynon Taf for a seven mile circular trail that starts and ends in Hirwaun. On his route he learns about the area's industrial past; visits a whisky distillery and takes a ride on the world's fastest seated zipline. Meanwhile wildlife expert Lizzie Daly investigates how otters are under threat and Onkar Singh Purewal goes on a trek with alpacas across the Brecon Beacons. MEDIUM: Weatherman Derek Brockway visits Hirwaun in Rhondda Cynon Taf to learn about the town's industrial heritage.

Derek and the team travel to the Elan Valley in Powys for a stunning seven-mile circular walk, punctuated by dams. He learns how the valley was flooded to supply water to Birmingham. On his way round he has a go a mountain biking and discovers the part the area played in the daring Dambusters attack in WW2. Meanwhile archaeologist Dr Erin Lloyd Jones visit the ruins of the ancient abbey at Strata Florida and performer Jonny Cotsen meets military veterans who are being inspired and helped through art.