Radzi Chinyanganya loves sport. He also loves a challenge. So Blue Peter surprised him with the daunting task of climbing the world's highest artificial climbing wall. With only 16 weeks to prepare, Radzi learns how to climb from scratch. To hone his technique and reach higher and higher heights, quite literally, Radzi faces an abseil window clean on the Wales Millennium Centre, tackles a dizzying via ferrata and visits the Lake District for his very first outdoor rock climb. But will Radzi be able to take on the ultimate gravity-defying climb of epic proportions? His final challenge is to scale the face of the Diga di Luzzone in Switzerland, a 165-metre-high man-made climbing wall like no other! Show less