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World’s longest underwater cave system runs 524 km, dwarfing Grand Canyon

The world’s longest underwater cave system now stretches an astonishing 524 Kilometers, a hidden labyrinth that, in raw ...

From prehistoric sharks to unusual flowers: What’s inside the world’s largest cave

Mammoth Cave National Park, home to the world’s longest known cave system, stretches for more than 680 kilometres, and counting, into the Earth. What began as a limestone labyrinth has turned out to ...