Lakes of Ounianga

Eighteen lakes lie in two groups in one of the driest corners of the Sahara, fed by fossil groundwater rather than by any rain that falls on them now. Yoa in the northern group is deep and hypersaline. Several of the southern lakes stay fresh because floating mats of reed cover them and hold the evaporation down, which is the oddity that carried the whole site onto the world heritage list. The colours run from deep blue through green to rust, ringed by palm belts and orange dunes. Nothing is built here and it is reached only across days of open desert.