An earthquake on Dec. 16, 1811 caused parts of the Mississippi River to flow backwards.
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Australia's Great Barrier Reef is 1,250 miles long!
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If Antarctica's ice sheets melted, the worlds oceans would rise by 60 to 65 metres (200 - 210ft) - everywhere
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The Niagara Falls moves upstream at an average rate of about 295ft a century!
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The Caspian Sea is also classed as the world's largest lake.
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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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