The Sahara is the largest hot desert in the world and the third-largest desert overall, spanning across North Africa. It covers an area of approximately 9.2 million square kilometers (3.6 million square miles) and stretches from the Red Sea in the east to the Atlantic Ocean in the west, and from the Mediterranean Sea in the north to the Sahel region in the south. The name "Sahara" comes from the Arabic word for "desert." The desert's landscape includes sand dunes, stone plateaus, gravel plains, dry valleys, and salt flats, with features like the highest point at Mount Koussi (3,415 meters) and the lowest point at the Qattara Depression (133 meters below sea level). The Sahara is divided into several regions and has a complex ecology influenced by alternating desert and savanna cycles over thousands of years.
