An earthquake on Dec. 16, 1811 caused parts of the Mississippi River to flow backwards.
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The city of Houston, Texas is built on a swamp and is slowly sinking!
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The North Atlantic gets 2.5 centimetres (1in) wider every year.
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It's still possible to see the division between East and West Germany due to different light bulbs.
5
Due to gravitational effects, you weigh slightly less when the moon is directly overhead.
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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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