Lake Turkana is the largest permanent desert lake on Earth — a jade-green inland sea stretching more than 250 kilometres through the black-lava badlands of Kenya's far north. Fed almost entirely by Ethiopia's Omo River and with no outlet, it loses water only to evaporation, concentrating the algae that rise to the surface in calm weather and stain it a cloudy jade — the reason it has long been called the Jade Sea. It is also the world's largest alkaline lake, and the sediment beds around its shores hold one of the richest records of human origins anywhere: Turkana Boy, a near-complete Homo erectus skeleton of a youth who lived about 1.6 million years ago, was lifted from the western shore in 1984. Two active volcanic islands, Central and South, still steam above their crater lakes, and the national parks that ring the water are a UNESCO World Heritage Site for both the fossils and the otherworldly land.
Reaching the lake means crossing some of Kenya's harshest country — lava fields, bare desert, and the grazing lands of Turkana and Samburu herders. The reward is the colour itself, turquoise shallows deepening to jade against black rock and pale sand, with Nile crocodiles basking along the margins in one of the largest concentrations left in Africa. Evening is the lake's finest hour: the wind that whips up most afternoons finally drops, the water flattens to glass, and fishing boats slip out silhouetted against a sky gone molten orange. That colour now comes with a warning — since Ethiopia's Gibe III dam began regulating the Omo in 2015, far less water reaches the lake, and in 2018 UNESCO added it to the List of World Heritage in Danger.