The Sahara is an enormous expanse of sand, gravel and rocks. The desert stretches some 8,370 km (5,200 miles) from east to west and covers 9,200,000 km² (3,600,000 sq mi), or roughly the size of the United States and it is slowly but surely growing. The name 'Sahara' is derived from Arabic word of ṣaḥrā' (صَحَارَى), meaning 'desert'.

It is one of the hottest and driest places on earth and yet, more people drown in the Sahara than die from exposure or thirst. That is because of the short, but devastating rains that hit the desert sometimes. You might also not expect to find any snow in the Sahara, but the opposite is true. In the central region are the snowcapped peaks of Emi Koussi and Tahat. During the winter, temperatures in the desert region drop as low as 14°C (57°F).

About 25% of the Sahara Desert is sand. The rest consists of gravel-covered plains, rock-strewn plateaus and volcanic mountains. At some places the sand dunes stretch for several hundred kilometers and reach a height of 300 m (1,000 feet).

Desert storms can cause sand to whip up 1.5 km (1 mile) and cover everything in its path with a thick layer of dust. The town of Timbuktu, for example, is slowly being buried under the sand. Nowadays you have to step down from street-level to get into many of the houses. The Sahara is slowly expanding, as the winds move the sand dunes around. Ironically it are the sand dunes that make the Sahara so appealing. The Ténéré Desert in Niger has some of the most awe-inspiring dunes in the world. At other places, volcanic mountains, occasional green oases and even waterfalls can be found.

The Tuareg are the only inhabitants of the Sahara. They are nomadic desert dwellers and wouldn't like to live anywhere else. They say that when the wind stops blowing, you can hear the earth turn, so quiet it can get in the desert. Most of the time the wind blows, though.

The Sahara is not a very gentle or domesticated region, but if you're looking for a sublime experience, you should take a tour on a Tuareg camel and experience the Sahara at night. This is when then air is crisp and clear, the stars appear to be so close you could touch them and the silence is absolutely frightening.

The Sahara Desert covers large parts of Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Sudan and Western Sahara.

The Sahara Desert is bounded by the Mediterranean Sea in the north and the semi-arid tropical savanna of the Sahel region in the south. From east to west it stretches between the Red Sea and the Atlantic Ocean.

The Sahara alternates between desert and savanna grassland in a 20,000-year cycle that is caused by the precession of Earth's axis as it rotates around the Sun. This changes the location of the North African monsoon, causing the Sahara to be more dry, or wet.