The Answer:

The largest (nonpolar) desert in the world is the Sahara, in north Africa, which spans an area measured at roughly 3.5 million square miles.

The United States' contiguous 48 states could easily fit in the desert.

It spans more than 3,000 miles across Africa, stretching from the Atlantic Ocean to the Red Sea. It is bordered by the Mediterranean Sea on the north and it spreads all the way down to central Africa, some 1,200 miles south.

For a list of the rest of the world's largest desert regions, check out our table of Principal Deserts of the World.

—The Editors