Secrets of the London Underground

Tim Dunn and Siddy Holloway explore the abandoned underground branch line between Holborn and Aldwych. At Holloway Road, they find out about the Tube network's only spiral escalator.

Tim Dunn and Siddy Holloway visit North End under Hampstead Heath. The station was abandoned before it was ever completed, however the station took on a new life when it became a Cold War bunker.

Tim Dunn and Siddy Holloway explore the disused parts of Piccadilly Circus, the grandest station on the London Underground, and visit the long-abandoned Highgate surface station.

Tim Dunn and Siddy Holloway explore the hidden parts of Euston, including unique features not found elsewhere.

Tim Dunn and Siddy Holloway go on a late-night exploration of two of London's least known stations. St Mary's and the original Aldgate East are only a few hundred metres apart but trains haven't stopped at either since 1938.

Tim Dunn and Siddy Holloway explore Clapham South's deep level shelter where thousands of Londoners slept during World War II.