The Sahara Desert is the world’s largest hot desert, stretching across much of North Africa.
The Sahara covers approximately 9.2 million square kilometres, making it comparable in area to the United States or China. It extends across countries including Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Sudan, and Tunisia.
The desert is not made entirely of sand. Sand seas and dunes occupy only part of its landscape; broad gravel plains, rocky plateaus, mountains, salt flats, and dry valleys are also common. The Tibesti Mountains and Ahaggar Mountains are among its elevated regions.
The Sahara has not always been equally dry. During the African Hum湿 Period, roughly 11,000 to 5,000 years ago, monsoon rainfall created lakes, grasslands, and habitats for abundant wildlife. Rock art from that period records cattle, giraffes, and other animals in areas that are now extremely arid.