The longest cave in the world is the 'Mammoth Cave System' in the USA at 560,000 mtrs deep!
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Forest fires move faster uphill than downhill.
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It takes a drop of ocean water more than 1,000 years to circulate around the world.
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The Dallas/Ft. Worth airport is larger than New York City's Manhattan Island.
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A waterfall known as The Devil's Kettle empties water into a hole and nobody knows where it ends up!
18
There's a lake under Antarctica that is 25 million years old called Lake Vostok.
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Mexico City is built on top of an underground resevoir!
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