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
Mexico City is built on top of an underground resevoir!
47
The state with the longest coastline in the Continental U.S. is Michigan.
31
It takes a drop of ocean water more than 1,000 years to circulate around the world.
61
Forest fires move faster uphill than downhill.
52
10 of the tributaries flowing into the Amazon river are as big as the Mississippi river.
41
Europe is the only continent without a desert.
62