The Grand Canyon contains rocks 1.8 billion years old — nearly half the age of the Earth.

The Colosseum in Rome could hold between 50,000 and 80,000 spectators and had a retractable awning called the velarium.

Angel Falls in Venezuela is the world's highest uninterrupted waterfall at 979 meters.

Russia spans 11 time zones and is so wide that the sun is setting in the west as it rises in the east.

The United States purchased Florida from Spain in 1819.

Urban populations now exceed rural populations worldwide.

Ancient volcanic eruptions shaped prehistoric environments.

Canada has more lakes than the rest of the world combined.

The Amazon River basin covers millions of square kilometers.