The Sahara is the largest arid desert in the world. The European Union would fit twice into its nine million square kilometers. It occupies almost all of northern Africa. Only Antarctica is larger, but it is a cold, wet desert of ice and snow.
The sea used to wash over the area several times. A few thousand years ago it was much wetter there. Big animals like giraffes and also crocodiles lived there.
Today, however, the Sahara is a desert and water is very scarce. You can only find it in the ground and bring it up with wells. There are sometimes oases around such wells. There are wadis, which are rivers that only have water at certain times of the year. Only the rivers Nile and Niger carry water constantly.
However, only about a fifth of the Sahara consists of sandy areas. Most of the areas are covered with stones and rocks. The highest mountain is Emi Koussi in the state of Chad, at 3415 meters. It is hot in the Sahara, on average 40 degrees Celsius, sometimes even 47.
Only about four million people live in the huge area. The largest city is called Nuakschott and is the capital of Mauritania. This country is also where most of the Saharans live.
The north of the Sahara follows the coast of the Mediterranean Sea, in the west of the Atlantic. Rainforest is south of the Sahara. But between the desert and the rainforest, there is another landscape, the savannah. It is similar to the desert but has more water, plants, and animals.