Salar de Uyuni, Bolivia

Salar de Uyuni commands attention as the world's largest salt flat, spanning 10,582 square kilometers of blinding white at 3,656 meters elevation, with a mirror effect during the rainy season that attracts over 200,000 tourists annually. Beneath the crust lies an estimated 21 million tonnes of lithium, representing 50 to 70 percent of global reserves—a resource value that dwarfs any wetland formation on this list. While #5 Antelope Canyon sees 1.2 million visitors, Uyuni's remote location limits tourism but amplifies its surreal appeal, with a 30-centimeter-thick crust supporting vehicles up to 3 tons—outperforming #8 Waitomo Caves' fragile limestone chambers in sheer robustness, as the crust withstands 250 megapascals pressure compared to Waitomo's 10 megapascals. Its lithium brine concentration at 0.03% reinforces its ranking as the planet's largest lithium deposit, underscoring economic importance exceeding typical tourist landmarks.