Salar de Uyuni, Bolivia
The world's largest salt flat covers 4,000 square miles of Bolivian altiplano. In the dry season, it's an endless white sheet of salt tiles made all the more dazzling by clear, sunny skies. November through March, regular rains create a mirror effect that merges lake and sky. No matter when you see it, Salar de Uyuni is one of the most captivating sights on earth.