Chad contains the Sahara’s Ounianga Lakes, a UNESCO-listed chain of desert lakes in the Ennedi region.
The lakes lie in a remarkably dry part of northeastern Chad, where annual rainfall is extremely low. Their continued existence is linked to groundwater stored beneath the desert, which reaches the surface in a natural basin. Different lakes vary in salinity, depth, color, and vegetation, even though they occupy the same broad desert landscape.
UNESCO inscribed the Lakes of Ounianga as a World Heritage Site in 2012. The site includes 18 interconnected or nearby lakes divided into two groups: Ounianga Kebir and Ounianga Serir. Ounianga Kebir contains the largest lakes, while Ounianga Serir has many smaller bodies surrounded by reeds and palms.
The lakes are not remnants of a single modern river. Their water is chiefly fossil groundwater, accumulated during wetter climatic periods and replenished only slowly. This makes them valuable evidence of the Sahara’s changing climate and ancient hydrology.