Rob Bell explores the story and construction of the world's most iconic bridges. The Millau Viaduct over the Tarn gorge in southern France is the world's tallest bridge and considered by many to be the world's most beautiful. Rob meets the design team, including architect Lord Norman Foster and structural engineer Dr Michel Virlogeux, and learns about the innovative and ancient techniques used to build it. London's Millennium Bridge, Lord Foster's other project at the time, is also featured, including what caused the wobble and how it was rectified.