The Caspian Sea is also classed as the world's largest lake.
52
More than a dozen men have stood on the surface of the moon, but only three have been to Challenger Deep in the Marianas Trench, the deepest known spot in the ocean.
17
There's a lake under Antarctica that is 25 million years old called Lake Vostok.
109
The state with the longest coastline in the Continental U.S. is Michigan.
31
Even Antarctica has an area code. It's 672.
58
One cubic mile of seawater contains about 50 pounds of gold.
79
An earthquake on Dec. 16, 1811 caused parts of the Mississippi River to flow backwards.
243
It takes a drop of ocean water more than 1,000 years to circulate around the world.
61