The Koro Toro settlement and maximum security prison is situated on the eastern boundary of the desert.

To the west is the Ténéré desert (the Erg of Bilma) of western Chad and Niger, to the north are the Tibesti Mountains of the central Sahara.

[6][7] In 2001, the type fossil of Sahelanthropus tchadensis, a hominid species of about 7 million years ago, was discovered at Toros-Menalla (16°15′N 17°30′E / 16.25°N 17.5°E / 16.25; 17.5, some 100 km north of Salal), at 250 meters above sea level.

[2][6][8] Michel Brunet, since 1994, has explored Miocene and Pliocene deposits in the desert with the Mission Paléoanthropologique Franco-Tchadienne, which are located in a basin which includes Lake Chad.

[4] In the period of the Sahelanthropus tchadensis, desert would have long dry season, and fruits would have been able to grow at certain times of the year.