1: 1. The Wave, Arizona - A mesmerizing sandstone formation in the Coyote Buttes region. 2. Giant's Causeway, Northern Ireland - Hexagonal basalt pillars on the coast. 3. Arches National Park, Utah - Natural arches and red-rock formations abound.

2: 4. Ayers Rock (Uluru), Australia - Sacred monolith in the Outback. 5. Moeraki Boulders, New Zealand - Large, spherical boulders on the beach. 6. Stone Forest, China - Limestone formations resembling trees.

3: 7. Fairy Chimneys, Turkey - Cone-shaped rock formations in Cappadocia. 8. The Great Dune of Pyla, France - Europe's tallest sand dune near Bordeaux. 9. Sugarloaf Mountain, Brazil - Iconic peak in Rio de Janeiro.

4: 10. Trolltunga, Norway - Dramatic cliff jutting out above Lake Ringedalsvatnet. 11. The Twelve Apostles, Australia - Limestone stacks off the coast of Victoria. 12. Spotted Lake, Canada - Unique polka-dotted lake in British Columbia.

5: 13. Bryce Canyon, Utah - Hoodoos and natural amphitheaters carved by erosion. 14. The Giant's Kettles, Norway - Whirlpool-like depressions in the rocks. 15. Meteora, Greece - Monasteries perched atop towering rock pillars.

6: 16. The Cliffs of Moher, Ireland - Majestic sea cliffs rising along the coast. 17. The Needles, South Dakota - Rock spires in the Black Hills. 18. Wave Rock, Australia - Wave-like granite formation in Western Australia.

7: 19. Mount Rushmore, South Dakota - Iconic presidential carvings in the Black Hills. 20. The White Desert, Egypt - Surreal limestone formations in the Western Sahara. 21. The Devil's Tower, Wyoming - Intriguing igneous rock column sacred to Native Americans.

8: 22. The Blue Mountains, Australia - Eucalyptus-covered peaks and rock formations. 23. Zuma Rock, Nigeria - Monolithic rock near the capital, Abuja. 24. The Door to Hell, Turkmenistan - Fiery crater in the desert burning since 1971.

9: 25. The Old Man of Hoy, Scotland - Sea stack off the coast of Orkney. 26. Valley of Fire, Nevada - Striking red sandstone formations near Las Vegas. 27. Belogradchik Rocks, Bulgaria - Unique rock formations in Northwestern Bulgaria.