Glenfinnan Viaduct, Caledonian Sleeper, West Highland Line

Cameras follow The Jacobite steam train across the Glenfinnan Viaduct. Vloggers Geoff and Vicki, who have visited all 2,567 of Britain's railway stations, board the Caledonian Sleeper on a 24-hour return journey to the UK's highest station at Corrour. Plus, a team of engineers scramble to erect the UK's largest landslide barrier when a slip threatens a section of the world-famous West Highland Line.