TV and radio presenter Chris Tarrant journeys by rail through some of the world's most challenging terrain, beginning with a trip from Bangkok in Thailand to Mandalay in Myanmar. Chris traces the route of the notorious Burma-Siam Railway, a 250-mile long line built by the Japanese during World War Two using enslaved Asian workers and Allied Prisoners of War, visiting the famous site of the Bridge on the River Kwai along the way.

Chris continues his exploration of the world's most extreme railway lines. He attempts to cross the Andes, setting off from the coast of Chile and heading for the Bolivian capital of Sucre. Along the way he traverses some of the driest and most inhospitable environments on the planet, hitches rides on unusual trains and deals with altitude sickness at more than 3,000 metres.

The TV presenter continues his travels along the world's most challenging railways, setting out to reach the northernmost railway station on Earth, inside Russia's Arctic Circle. This is an epic 2,000-mile adventure from Moscow into Arctic Siberia, and begins with a marathon 19-hour leg. Along the way he enjoys a reindeer stew with a local family and takes the controls of one of the massive locomotives that power the trains, before pressing on along railways built under the brutal regime of Joseph Stalin.

Chris attempts to cross the length of Cuba, the only island in the Caribbean to boast an extensive railway network, from Havana in the west to the far east of the island.

Documentary series in which Chris Tarrant explores the world's most extreme railway lines. Chris discovers how a 2,500-mile transcontinental railway was built against huge odds in just a few decades, and turned a vast wilderness of isolated communities into the country we now know as Canada.