Secrets of the London Underground

Tim Dunn and Siddy Holloway explore the shortest branch line on the London Underground network.

Siddy takes Tim on a mystery tour of a secret station deep beneath Hampstead Heath.

Tim and Siddy explore the disused parts of Piccadilly Circus.

Tim and Siddy have a night-time adventure as they go on a late-night exploration.

Tim and Siddy are deep beneath Clapham Common; they're so deep, the Northern line is running above their heads.