The world's largest cave system, spanning 1,553 miles, holds secrets of a tumultuous past, including the remnants of Nazi occupation, Soviet revolution, and Cold War espionage.
Aired: Oct 17, 2019Uncovering a long-forgotten city beneath the Rock of Gibraltar, archaeologist...
2. Mystery of the Lost Labyrinth
Aired: Oct 24, 2019The next episode takes place in a complex network of hidden tunnels within an...
3. Secrets of the Terror Tunnels
Aired: Oct 31, 2019Ancient tunnels, nearly 3,000 years old, have seen their fair share of epic b...
Aired: Nov 7, 2019The next episode takes us on a thrilling adventure as a team of experts delve...
Aired: Nov 14, 2019Uncovering Scotland's Hidden Underground Secrets: A network of mysterious vau...
Aired: Nov 21, 2019The world's largest cave system, spanning 1,553 miles, holds secrets of a tum...
Aired: Dec 5, 2019Next episode, a mysterious labyrinth of subterranean cisterns beneath Istanbu...
Aired: Dec 12, 2019In rural France, a hidden network of tunnels has been a secret sanctuary thro...
9. Conspiracy in the Buried City
Aired: Dec 19, 2019Archaeologists stumble upon a hidden city, five stories beneath the earth, re...
Aired: Dec 26, 2019Excavations in a long-abandoned cave network reveal the unsettling discovery ...
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Seasons: 2
Network: Science
Production Countries: United Kingdom, United States
Genres:Documentary
