Watch Hidden London Hangouts Season 4 Episode 3 Online
- COUNTRIES: United Kingdom
- Subtitles: English
In this epic episode the team go behind the scenes of the Northern line at London Bridge to explore the original tunnels of the City and South London Railway. Along the way they reveal how many of the tunnels have been reused in the modern station, discover a disused floodgate and find the tunnels of the world's first deep tube railway from 1890.
