Australia's Great Barrier Reef is 1,250 miles long!
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Israel's Dead Sea is 1,312 feet below sea level.
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Due to gravitational effects, you weigh slightly less when the moon is directly overhead.
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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 city of Houston, Texas is built on a swamp and is slowly sinking!
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A volcano has enough power to shoot ash as high as 50 km into the atmosphere.
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The North Atlantic gets 2.5 centimetres (1in) wider every year.
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The Caspian Sea is also classed as the world's largest lake.
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