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TVPGHDHidden Beneath the Cities1hNational Geographic
Scientists uncover salt chambers, bunkers, old kingdoms, and mysterious caves.
Scientists uncover salt chambers, bunkers, old kingdoms, and mysterious caves.
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Hidden Beneath the Cities
S1, EP1 "Underground Cities and Secret Chambers"Scientists uncover a city, a chamber, and a complex, and map a tunnel network.
Hidden Beneath the Cities
S1, EP2 "Crystal Cathedrals and Buried Bunkers"Scientists uncover salt chambers, bunkers, old kingdoms, and mysterious caves.
Uncovers the extraordinary worlds that exist beneath major urban centers, from the tombs and wartime shelters of Naples to the manmade Royston Cave in Hertfordshire, England.
Original Air Date: Feb 25, 2026
Rating: TVPG
Playback: HD
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