Hugh Dennis and Julia Bradbury are in the South Downs, where they discover that this gentle, rolling landscape of southern England had a dramatic ancient past. Hugh gets to grips with the chalk of the famous white cliffs, a landscape built under the ocean — and finds out at first hand why chalk cliffs are one of the most dangerous places to climb. He also discovers how the South Downs' rocky past created the perfect place for British hang-gliding, and explores a vast hidden mine, filled with unexpected treasures. Julia meets a giant of a racehorse, and finds out why it has grown so big on the chalky South Downs grasslands; and she discovers a strange rock, embedded in the soft chalk for millions of years, but which is as sharp as steel. Between them, Hugh and Julia uncover how the stories in our deepest past created the landscape itself, and discover a totally unexpected side to the countryside of southern England. For a country of its size, Britain has the biggest variety of geology on earth, which has created not only a beautiful landscape, but also a fascinating industrial heritage, a rich history and many legends.