Overview: Since the dawn of the 19th century, rail networks have overcome almost all nature can throw at them. But there's one environment that's their nemesis: water. Some of the world's greatest Railways have challenged engineering's greatest minds in their efforts to conquer our ‘water worlds'. Whether crossing the cyclone-prone Indian Ocean, travelling under the Bosphorus Strait directly through an earthquake zone, or carved through the sea cliffs of Italian Riviera, each railway has solved a seemingly impossible problem: to create some of the most dramatic train journeys in the world.