Supersized Earth traces the spectacular story of how humans have transformed our world in a generation.

In this episode, Dallas explores how we can travel further and faster than ever before - and how our desire to shrink the world is inspiring some of the most extraordinary engineering projects on the planet.

Dan Cruickshank explores the mysteries and secrets of the bridges that have made London what it is. He uncovers stories of bronze-age relics emerging from the Vauxhall shore, of why London Bridge was falling down.