Geography
Bolivia's salt flat turns into a sky-sized mirror each rainy season
Salar de Uyuni, the crust of a prehistoric lake, is the world's largest salt flat at roughly 10,582 square kilometres. When a thin sheet of rainwater covers its perfectly flat surface, it reflects the clouds and sky so precisely that the horizon seems to vanish. Beneath the salt lies one of the planet's largest known lithium reserves, locked in briny water under the crust.