Tim Dunn rides up Mt Snowdon's railway to visit the summit station. He also explores the world's largest mechanically operated signal box and discovers how a glass structure envelopes Strasbourg's 19th century station.

Tim Dunn visits the architecture of the Stockton & Darlington railway, the first passenger steam line in the world. He also finds out how Essex's enormous Chappel Viaduct was built and explores the beautiful stations of Stockholm's metro system.