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
Venice Island was built on a foundation of tree trunks. 1200 years later, those same trunks still support almost all of central Venice.
8
The city of Houston, Texas is built on a swamp and is slowly sinking!
89
It takes a drop of ocean water more than 1,000 years to circulate around the world.
61
Even Antarctica has an area code. It's 672.
58
Australia's Great Barrier Reef is 1,250 miles long!
45