Gaberoun is a relic. The lakes of the Ubari are the last shining remnants of a far wetter Sahara, pockets where ancient groundwater still reaches the surface in the low ground between the dunes. There is no rain to speak of and a brutal sun overhead, so evaporation concentrates whatever water seeps in, leaving Gaberoun intensely saline. The salinity is what makes swimming here so peculiar: the dense water buoys you up the way the Dead Sea does, and the experience is genuinely pleasant despite the brine and the company of small crustaceans. The dunes that cradle the lake tower above it, so that from the water's edge you look up at slopes of pale sand rising against the sky in every direction.

People once lived at Gaberoun, and they lived in part off the lake itself. A small community settled here, and among their foods were the tiny worm-like crustaceans, a kind of brine shrimp, that they harvested from the salty water. The trait earned the lake people of this sand sea a blunt nickname: Dawada, the worm eaters, after the red shrimp dried and ground into paste and cakes. It was an improbable livelihood, fishing protein out of a salt lake in the heart of the Sahara, but it sustained generations. In the 1980s the community was relocated out of the dunes to Wadi Bashir, a settlement of concrete apartments built south of the sand sea, ending centuries of life on the lakeshore.

On the northwestern shore, scattered among the date palms, the old village still stands in ruins. Mud-brick walls, roofless and softening back into the ground, mark where families once lived beside the water. The abandonment gives Gaberoun a doubled character: a place of startling natural beauty haunted by the recent past, the homes empty but not ancient, left within living memory. A modest tourist camp was later set up on the northeastern shore, with open patios, sleeping huts, and a souvenir shop, drawing the small number of travelers willing to cross the dunes. The palms shade both the living and the lost.

Gaberoun does not give itself up easily. The lake lies off the road that runs between Sabha and Ubari, but the road only gets you close. From a point roughly 150 kilometers west of Sabha, reaching the water means a 36-kilometer crossing by four-wheel drive straight through the dunes of the Ubari Sand Sea, also called the Ramlat Dawada. It is slow, hot, disorienting work, with the best months falling between October and May, when the climate softens and the summer mosquitoes thin out. Other lakes lie scattered across the same erg, Mandara, Um al-Maa, Mafo, each its own bright eye in the sand. Of them all, Gaberoun is the broadest and the most storied.

The Ubari lakes are not permanent fixtures so much as a slow-motion farewell. They survive on the same underground water that civilizations have tapped across the Fezzan for millennia, and several of the smaller lakes in the sand sea have shrunk dramatically or dried out entirely within recent decades as the water table beneath the dunes has fallen. A few, like Um al-Maa, hold on; others are now little more than salt-crusted hollows where blue water used to be. Gaberoun, the largest, endures for now, but its very existence is a reminder of how thin the margin is out here. A lake in the desert is a balance between what seeps in and what the sun takes away, and that balance is shifting. To stand on its shore is to look at something beautiful and quietly impermanent.