With characteristic passion and enthusiasm, Alan Titchmarsh takes an incredible voyage of discovery - from the frozen summit of Ben Nevis to the white sands of the temperate Isles of Scilly, and from the rain-drenched tip of western Ireland to the dry expanses of East Anglia.

To reveal the secrets hidden in the landscape, Alan descends a Yorkshire waterfall twice as high as Niagara Falls, climbs one of the highest mountains in Scotland and goes foraging with red squirrels in Formby. He travels back in time to find hippos roaming through Trafalgar Square, an immense forest that spreads from Land's End to John O'Groats, and prehistoric reptiles swimming in Britain's tropical seas.

In an inspiring and compelling series, Alan shows how the British landscape and wildlife have evolved through dramatic geological, climatic and human change, but he also examines the state of the land today and investigates the fresh challenges and responsibilities we face in a future that promises as many spectacular transformations as in the past.