Derek Brockway walks the Clywedog Valley Trail near Wrexham in North Wales. He learns the story of John Wilkinson, known as Iron Mad Jack, who revolutionised the iron industry and helps carve a duck from a cedar log. Meanwhile, wildlife expert Lizzie Daly discovers red squirrels are on a comeback in the area and Onkar Singh Purewal is blown away by the rare varieties of apples being grown on the National Trust's Erddig Estate