Derek the Weather is kissed by the sun in this episode which kicks off on the edge of the Rhondda Valley. He takes the plunge in The National Lido of Wales in Pontypridd on his walk between Porth and Taff's Well. 

But there's a serious element too as he follows a route commemorating the first mining disaster in Wales to claim more than 100 lives – many of them boy miners. 

Dr Erin Lloyd Jones tells the story of three young brothers who perished in that Cymmer Colliery tragedy of 1856 while Onkar Singh Purewal fizzes with excitement to learn about the history of the ‘Pop Factory' in Porth. 

Weatherman Derek Brockway explores the stunning Wye Valley on a walk which takes him from the ancient village of Trellech to the stunning market town of Monmouth. On the way he takes a dip in ‘Britain's favourite river', the Wye, and follows in the footsteps of Admiral Nelson. Meanwhile history hunter Dr Erin Lloyd Jones joins the search for a lost city and Matthew Bassett forages the woods and hedgerows for some edible delights.