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. Fire has long been our main source of energy and Iain shows how this meant that the planet played a crucial role in Britain's industrial revolution, whilst holding China's development back. Along the way he dives in a mysterious lake in Oregon, climbs a glacier of salt, crawls through an extraordinary cave in Iran and takes a therapeutic bath in crude oil.

Anthropologist Wade Davis and river advocate Robert F. Kennedy Jr journey down the Colorado River on a two-week expedition to highlight water conservation issues. Traveling by rafts, kayaks and wooden dories, they are accompanied by their daughters and guided by Shana Watahomigie, a Native American National Park ranger. Filmed with a 350-pound 3D camera, it involved the cooperation of three Indian nations, the National Park Service, film sponsor Teva’s team of kayakers and more than a dozen experienced river guides. The film explores America's drought and freshwater shortages, the impact on the river of damming, and human water supply needs. Grand Canyon Adventure: River at Risk was directed by Greg MacGillivray and narrated by Robert Redford.

In this episode he traces India in the days of the Roman Empire. In Kerala the spice trade opened India to the world, whilst gold and silk bazaars in the ancient city of Madurai were a delight for visiting Greek traders. From the deserts of Turkmenistan Michael travels down the Khyber Pass to Pakistan to discover a forgotten Indian Empire that opened up the Silk Route and at Peshawar built a lost Wonder of the World.

A visit to the Amazon jungle - the world's largest rainforest and home to the widest variety of plants and animals on Earth. he diversity of life in the jungle is so great that in just two square miles scientists have counted 3,000 varieties of ants, 530 types of birds and 11 species of monkey. But despite the huge range of life that flourishes here, survival is never easy.

Following the Yangtze along Tiger Leaping Gorge into Yunnan in China, Palin reaches the easternmost end of the Himalayas. He gets a medical check-up before exploring medieval Lijiang with the director of the local orchestra. Heading over Myanmar to Nagaland in India he rides the steam train to Tipong Coalmine. In Assam he rides an elephant and then stays in a strange monastery.

Deep in the Bolivian Andes at the height of 13,000ft stands Tiwanaku, the awe-inspiring ruins of a monolithic temple city. Built by a civilisation who dominated a vast swathe of South America, it was abandoned 1,000 years ago. For centuries it has been a mystery - how did a civilisation flourish at such an altitude and why did it vanish? Jago Cooper journeys through Bolivia's spectacular landscape to investigate the origins of Tiwanaku and finds evidence of an ancient people with amazing understanding of their environment, whose religion was based on collective effort and ritual beer drinking.