

Underground Worlds
Episodes
S1 E1 - Gibraltar
Watch on supported devicesJuly 6, 201944minNew discoveries reveal the secrets of a long-lost chamber with evidence of high-stakes espionage in a hidden subterranean city built within the Rock of Gibraltar.Watch for freeS1 E2 - Sweden
Watch on supported devicesJuly 13, 201944minExploring Sweden's passion for subterranean spaces, and how the nation has taken extraordinary precautions to protect itself - by excavating an astounding 65,000 nuclear bunkers.Watch for freeS1 E3 - Switzerland
Watch on supported devicesJuly 20, 201944minExamines some of Switzerland's 300,000 subterranean bunkers, the creation of an entrepreneur in England that's shrouded in mystery, and a network of man-made tunnels deep beneath Slovenia.Watch for freeS1 E4 - Kingdom of Salt
Watch on supported devicesJuly 27, 201944minThe Wieliczka Salt mine in Poland, some 327 metres deep, where the voids left behind from excavating salt have been transformed into extraordinary spaces, carved by hand.Watch for freeS1 E5 - Bouzincourt
Watch on supported devicesAugust 3, 201944minA labyrinth of tunnels underneath a tiny French village which contains mysteries from several historical eras, and a Welsh slate mine that has been given a new lease of life.Watch for freeS1 E6 - City of Naours
Watch on supported devicesAugust 10, 201944minExplores an underground city beneath a forest in Northern France built to house 3000 people, an ice cave under Iceland's biggest glacier, and a subterranean power station in London.Watch for freeS1 E7 - Jersey War Tunnels
Watch on supported devicesAugust 17, 201944minAn exploration of the underground bases built by the German army during the occupation of Jersey, and a group of more than 20 underground cities in Turkey, one of which dates back to 800 BCE.Watch for freeS1 E8 - The Maginot Line
Watch on supported devicesAugust 24, 201944minAn exploration of the secrets of the largest subterranean fortress along France's border with Germany, and a look at how a unique precious mineral was discovered in Derbyshire.Watch for freeS1 E9 - Edinburgh Vaults
Watch on supported devicesAugust 31, 201944minThe sinister history of Edinburgh's vaults and the development of Helsinki's subterranean spaces. Plus, the impact of the building of Naples on the volcanic ground below.Watch for freeS1 E10 - Dover War Rooms
Watch on supported devicesSeptember 7, 201944minExploring the military headquarters built beneath Dover Castle during the Second World War, and Odessa's catacombs, possibly the largest tunnel network in the world.Watch for free