Chris Tarrant: Extreme Railway Journeys: Conquering the Alps

The broadcaster returns to find out how railways have been central to the history of four very different parts of the world. He begins by embarking on a journey across the Alps, starting in Vienna, before navigating one of the worst avalanche zones in the world. He then heads for St Moritz on a railway that was made possible in part by British holiday pioneer Thomas Cook, before boarding two steep cog railways to climb up the north face of the Eiger to reach the 'Roof of Europe"