There's a lake under Antarctica that is 25 million years old called Lake Vostok.
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The Dallas/Ft. Worth airport is larger than New York City's Manhattan Island.
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The city of Houston, Texas is built on a swamp and is slowly sinking!
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Louisiana is the only state that grows in land area every year (Due to alluvial deposits from the Mississippi River).
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Every year, Alaska has about 5,000 earthquakes.
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The longest cave in the world is the 'Mammoth Cave System' in the USA at 560,000 mtrs deep!
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Due to gravitational effects, you weigh slightly less when the moon is directly overhead.
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