The Sahara Desert is the largest hot desert in the world, covering much of North Africa. It spans approximately 9 million square kilometers (3.6 million square miles), making up about 10% of the African continent. The Sahara is known for its vast stretches of sand dunes, but it also features rocky plateaus, mountain ranges, and dry salt flats. The desert has extreme temperatures, with daytime highs often exceeding 40°C (104°F) in summer, while nights can become much cooler. Despite the harsh environment, the Sahara is home to various unique flora and fauna, as well as several nomadic cultures that have adapted to the desert's conditions for centuries.