Australia's Great Barrier Reef is 1,250 miles long!
45
The Amazon rainforest produces more than 20% the world's oxygen supply.
182
An earthquake on Dec. 16, 1811 caused parts of the Mississippi River to flow backwards.
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The Caspian Sea is also classed as the world's largest lake.
52
The Niagara Falls moves upstream at an average rate of about 295ft a century!
48
The water of the Antarctica is so cold that nothing can rot there.
334