A waterfall known as The Devil's Kettle empties water into a hole and nobody knows where it ends up!
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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 takes a drop of ocean water more than 1,000 years to circulate around the world.
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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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Forest growth in the US has exceeded harvest since the 1940’s. Today, we have more trees than any time in the past 100 years.
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