Season 4 Episode
- Season 4 Earls Court and Alperton
- Season 4 Paddington and Tottenham Court Road
- Season 4 Waterloo and Marble Arch
- Season 4 South Kentish Town and London Underground Control Centre
- Season 4 Thames Tunnel and Lambeth North
- Season 4 Ruislip Depot and Warren Street
- Season 4 Northumberland Park and Finsbury Park
- Season 4 Stockwell and The DLR
- Season 4 Gloucester Road
- Season 4 Old Street
Secrets of the London Underground
7.40 44 minutes Railway historian Tim Dunn and Siddy Holloway from the London Transport Museum explore hidden areas of the London Underground that—despite being just feet away from where millions of people regularly travel—hardly anyone knows about. The pair will explore abandoned tunnels, secret bunkers and hidden staircases that have been concealed from public view for years.
