The longest cave in the world is the 'Mammoth Cave System' in the USA at 560,000 mtrs deep!
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Every year, Alaska has about 5,000 earthquakes.
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One cubic mile of seawater contains about 50 pounds of gold.
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The state with the longest coastline in the Continental U.S. is Michigan.
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More than a dozen men have stood on the surface of the moon, but only three have been to Challenger Deep in the Marianas Trench, the deepest known spot in the ocean.
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A waterfall known as The Devil's Kettle empties water into a hole and nobody knows where it ends up!
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