Bolivia

The world’s largest salt flats are fundamentally a whole lot of nothing — which is, paradoxically, why they’re so fascinating. Weird and surreal, you might just be convinced that Salar de Uyuni exists in a parallel universe. When its surface is coated in a drizzle of rain, the vast and empty white crust transforms into a mammoth, kaleidoscopic mirror, reflecting the sky and anything on the horizon, setting the stage for dozens of imagery illusions. This is geology at its most sublime: packed with 10 billion tonnes of sodium chloride, the flats sprawl at a dizzying Andean altitude of nearly 12,00ft, and are so extraordinarily flat that NASA chooses to calibrate satellite sensors here. Unsurprisingly, it’s also a major centre of salt extraction — even nearby hotels are crafted from its salt.