The Gorges are several kilometers long natural valley with deep ravines through which the Thelja Wadi runs a very sinuous course towards the Chott El Gharsa.

An area of 675 ha is protected as Ramsar wetland, where the wadi's waters are present all year around (albeit with a very small flowrate).

The site contains 45 types of plants and trees among which: esparto or "alfa" grass Macrochloa tenacissima, compact rush Juncus conglomeratus, French tamarisk Tamarix gallica, caper Capparis spinosa, le Batoum, canes Arundo donax and bridal broom Retama monosper The most noticeable animals are the endangered Golden Eagle Aquila chrysaetos and the lizard Uromastyx acanthinura, known for its ability to wistand extreme desert conditions.

In addition, the following animals are encountered in the area and justify the need to protect their habitats: the spotted hyena Crocuta crocuta, the extremely rare Rüppell's sand fox Vulpes rueppellii, the African wildcat Felis silvestris lybica, the Tunisian (or Nabeul) tortoise Testudo graeca nabeulensis, the desert monitor Varanus griseus, the long-nosed leopard lizard Gambelia wislizenii, the European turtle dove Streptopelia turtur, the European bee-eater merops apiaster, the Montpellier snake Malpolon monspessulanus, The Moorish viper (Daboia mauritanica) and the Saharan horned viper Cerastes cerastes

For birds, in addition to the endangered golden eagle, the gorges also host the Eurasian eagle-owl (Bubo bubo), the Barbary partridge Alectoris barbara, the rock dove Columba livia, the European turtle dove (Streptopelia turtur), the crag martin (Ptyonoprogne rupestris) and the collared sand martin (Riparia riparia) The site is potentially threatened by pollution as a result of the mining activities carried out upstream and constructions related to tourism, but it is part of a presidential programme created in 2009 to preserve the biotopes, reinforce the biological diversity, encourage ecological tourism, and support scientific research and tourism.