In southwestern Bolivia, high in the Andes, Salar de Uyuni is the world's largest salt flat, covering 10,500 square kilometres. Its surface is almost perfectly flat for kilometres, and during the dry season the salt crust breaks into regular hexagonal patterns that continue in white all the way to the horizon. During the rainy season, heaviest in January and February, a thin layer of water turns the flat into a vast mirror. The sky seems to continue beneath your feet, the horizon disappears, and walking across the surface can feel like moving through the sky itself. Incahuasi Island rises abruptly from this expanse at its centre, covered with centuries-old giant cacti and standing on the exposed fossil remains of an ancient coral reef. The immense salt plain itself was formed from layers of salt and minerals left behind as a huge prehistoric lake system gradually dried up.
Salar de Uyuni is more than an endless white surface. As you move towards its edges and the surrounding high plateau, the landscape changes into a succession of salt-harvesting areas and volcanic peaks, with the vividly coloured lagoons of the Eduardo Avaroa reserve further south, where flamingos gather. The flat is usually explored by four-wheel-drive vehicles, and in the dry months, roughly May to November, they can reach Incahuasi. Its scale becomes easier to understand when you realise how quickly you lose any sense of direction: for kilometres, there may be almost no reference point beyond the horizon. Beneath this apparently empty landscape lies a resource with global economic importance; Salar de Uyuni contains an immense brine reserve associated with one of the world's largest known lithium resources. By day, the plain is defined by intense white light; by night, its high-altitude setting reveals an exceptionally clear sky. Salar de Uyuni is therefore not simply a landscape to look at, but a place whose scale only becomes fully understandable once you are inside it.