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
The city of Houston, Texas is built on a swamp and is slowly sinking!
89
It's still possible to see the division between East and West Germany due to different light bulbs.
5
If Manhattan had the same population density as Alaska, there would only be 15 people living there.
138
It takes a drop of ocean water more than 1,000 years to circulate around the world.
61
Australia's Great Barrier Reef is 1,250 miles long!
45
Even Antarctica has an area code. It's 672.
58