he Sahara, multiple ground, 9 million km² of desert, from the Atlantic to the Red Sea! The south of Algeria, Saharan area, represents a vast territory of approximately 2 million km².
In the center of this area, the Hoggar (Ahaggar) is a mountainous, volcanic solid mass, located between the 12' and the 13’ parallel of the Northern hemisphere, crossed by the tropic of Cancer to 80 km at the north of Tamanrasset. It covers a surface of approximately 540.000 km², which is about the quarter of the total surface of Algeria.
The Ahaggar is dominated by a kind of plateau, the Atakor. The Atakor is an enormous volcanic massive of the tertiary and quaternary eras. It is one of the most picturesque areas of the Ahaggar. Of the 150 volcanic peaks, which account the Ahaggar, just the Atakor counts 125 volcanic peaks of a very great beauty.
The most important volcanos and best known in the Atakor are the Tahat mountain, 3003 meters with a mountainous relief, the Ilamane peak, 2780 meters as a sugar loaf relief, and the Assekrem plateau, 2760 meters, made famous for the hermitage installed in 1910 by father Charles De Foucauld.
Around the Ahaggar, one finds theTassili, where rocks and sand are mixed; most known are: the Tassili Ahaggar (300 km South-East of Tamanrasset) and the Tassili N’Ajjer (600 km in the North-East of Tamanrasset).
The Tassilis areas are of a common geological composition. They offer however a large variety of landscapes.
It is where one finds mushrooms, domes and cathedrals of stone, separated by dunes of yellow or more or less red sand according to the places.
Humankind is present in the Sahara since 1 or 2 million years. It was the beginning of a hot and wet Sahara. Animals such as the rhinoceros, the hippopotamus and the crocodile have lived and shared the natural environment with the prehistoric man, such as innumerable paintings and rupestral engravings of Wadi of Djanet, the Tassili N’Ajjer and the Hoggar testify. A few millenia afterwards engravings and paintings of elephants, giraffes, antelopes and large herds of cattle, appear, witnessed by less wet grounds.
The dryness settled gradually, and it was the appearance of the horse and carts (Garamants) and finally, the camel, which announces the birth of the desert! (dry Climate).