Tim Dunn goes behind the scenes at London's Kings Cross station, where he learns about the heritage of the incredible listed building and the complications of adding a brand new extension. Tim also finds out about the disused funicular railway hidden in the Avon Gorge in Bristol. He learns about the world's largest and highest brick viaduct in the world in the German state of Saxony and Tim also visits a station in Dartmouth, Devon that's never had a train.

Tim Dunn follows his family roots by exploring the architecture in Metroland to the north west of London. He also sees the ornate Great Malvern station and its secret "Worm" passage and he experiences the extraordinary Glacier Express in Switzerland.