Wind shaped sand dunes adorn the vast desert that is the Sahara which is the world's largest hot desert and the world's second largest desert after Antarctica. At over 9,000,000 square kilometres it covers most parts of Northern Africa; an area stretching from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean.
The Sahara is almost as large as the United States, and is larger than Australia. The Sahara has an intermittent history that may go back as much as 3 million years. Some of the sand dunes can reach 180 meters (600ft) in height.
Photography by John Woodworth.