![](https://assets.tv24.co/channels/yesterday-2-l.webp)
Aired Monday July 29,
2:10am - 3:00amon U&Yesterday
Underground Worlds
Series 2 Episode 3: Cincinnati's Secret CavernsExploring the forgotten underworld hiding beneath the streets of Cincinati, USA. Plus, a state-of-the-art Cold War fortress on the shores of Denmark.
- Category
- Documentary
- Original air date
- 2022-01-24
Cast and crew