ANCIENT BUILDINGS BURRIED IN SALT? Salar de Uyuni, amid the Andes in southwest Bolivia, is the world’s largest salt flat. It’s the legacy of a prehistoric lake that went dry, leaving behind a desertlike, 11,000-sq.-km. landscape of bright-white salt, rock formations and cacti-studded islands. Its otherworldly expanse can be observed from central Incahuasi Island. Though wildlife is rare in this unique ecosystem, it does harbor many pink flamingos.