This is high up on my list:: World's largest salt flat located at Salar de Uyuni, Bolivia. During the rainy season, the water turns into the world's largest mirror. It's called the border between heaven and earth.
Salar de Uyuni (Bolivia) is the world's largest salt flat at square kilometers. It is located in the Potosí and Oruro departments in southwest Bolivia, near the crest of the Andes, and is at an elevation of meters above mean sea level.