The longest cave in the world is the 'Mammoth Cave System' in the USA at 560,000 mtrs deep!
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The city of Houston, Texas is built on a swamp and is slowly sinking!
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Every person in the world can fit in Texas and be given over 1000 sq ft in which to live.
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The state with the longest coastline in the Continental U.S. is Michigan.
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The state of Florida is bigger than England!
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Mexico City is built on top of an underground resevoir!
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Australia's Great Barrier Reef is 1,250 miles long!
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The water between India and Sri Lanka is only 3-30 feet deep and was purportedly passable on foot until 1480 AD when a cyclone moved some sand around.
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