Professor Iain Stewart tells the epic story of how geology, geography and climate have influenced mankind.In this first episode, Iain explores the relationship between the deep Earth and the development of human civilisation. He visits an extraordinary crystal cave in Mexico, drops down a hole in the Iranian desert and crawls through seven-thousand-year-old tunnels in Israel.

Professor Iain Stewart continues his epic exploration of how the planet has shaped human history.This time he explores our complex relationship with water. Visiting spectacular locations in Iceland, the Middle East and India, Iain shows how control over water has been central to human existence.

Professor Iain Stewart explores the story of our turbulent relationship with the wind.

Iain explores man\'s relationship with fire. He begins by embarking on an extraordinary encounter with this terrifying force of nature - a walk right through the heart of a raging fire.

It\'s easy to think of the human impact on the planet as a negative one, but as this programme discovers, this isn\'t always the case.It is clear that humans have unprecedented control over many of the planet\'s geological cycles; the question is, how will the human race use this power?