The highest navigable lake in the world is Lake Titicaca, shared between Peru and Bolivia at 12,507 feet.

The Great Rift Valley in Africa may eventually split the continent in two, forming a new ocean in millions of years.

The coldest temperature recorded on Earth occurred in Antarctica.

Hawaii is moving toward Japan at about 3 inches per year.

The Caspian Sea is the world's largest inland body of water and is classified as a lake despite its salt water.

The Great Wall of China spans thousands of miles.

Petra in Jordan was carved into rose-colored rock cliffs.

There are caves on Earth so deep they have their own weather systems.

Mount Etna in Sicily is Europe's most active volcano and has been erupting continuously for at least 2,700 years.