The Tagant closely resembles the Adrar; like it, it is besieged by the sands (the Aouker erg), it presents high cliffs, it is carved by deep wadis dotted with oases (El Barkat, N'Beïka, …) and disappears to the north beneath the Ek Khatt plain that separates it from the Adrar. To the east of the Tagant, the Aouker erg shelters the superb oases of Tichitt and Oualata.
According to some learned Moors, Tagant may be the Berber form of Ghana; the Tagant would thus be the last province still bearing the name of the ancient empire that Black Africans call Ganata and the Arabs Ghâna.
Nestled against the Dhar, Oualata is a ksar without ramparts whose houses, built up against one another, make it a city closed to foreign eyes; the walls are covered in banco of an astonishingly vivid red, which the women decorate with white arabesques painted with their fingers around the inner doors or on the façades.
Tichitt is the most isolated of the four ancient cities — indeed of all Mauritania: the most direct route runs from Tidjikja, the capital of the Tagant, over a distance of 260 km, reached by a sandy, rocky passage that is neither marked nor waymarked. The city grew with the trans-Saharan trade between Ouadane and Oualata; it was home to scholars researching every field, and the thousands of ancient manuscripts and libraries found there today bear witness to this wealth.