The Mid-Atlantic Ridge runs down the center of the Atlantic Ocean and is one of Earth's most volcanically active regions.

There are places on Earth that have never been explored.

Lake Baikal is the deepest freshwater lake in the world.

The Earth's crust is thinner beneath oceans.

The Nile River has supported civilizations for thousands of years.

The Angel Falls in Venezuela is the world's highest uninterrupted waterfall at 3,212 feet.

Mount Everest is not the closest point to space — that title goes to Mount Chimborazo in Ecuador due to Earth's equatorial bulge.

The Gotthard Base Tunnel is one of the longest railway tunnels in the world.

The shortest commercial flight in the world is between two Scottish islands — it lasts about 90 seconds.