The 25 most popular tourist attractions in the world

24. Petronas Twin Towers, Kuala Lumpur, Malaysia

23. Sydney Opera House, Sydney, Australia

22. Chichen Itza, Yucatan, Mexico

21. Wat Pho, Bangkok, Thailand

20. The National September 11 Memorial, New York City, New York

19. Burj Khalifa, Dubai, United Arab Emirates

18. Lincoln Memorial, Washington DC

17. Great Wall at Mutianyu, China

16. Charles Bridge, Prague, Czech Republic

15. Hagia Sophia, Istanbul, Turkey

14. The Alhambra, Granada, Spain

13. Notre Dame Cathedral, Paris, France

12. Church of the Savior on Blood, St. Petersburg, Russia

11. Eiffel Tower, Paris, France

10. Golden Gate Bridge, San Francisco, California

9. Cristo Redentor, Rio de Janeiro, Brazil

8. Alcatraz, San Francisco, California

7. Milan Cathedral, Milan, Italy

6. St. Peter's Basilica, Vatican City

5. La Sagrada Familia, Barcelona, Spain

4. Sheikh Zayed Grand Mosque, Abu Dhabi, United Arab Emirates

3. Taj Mahal, Agra, India

2. Machu Picchu, Peru

1. Angkor Wat, Siem Reap, Cambodia

You've seen the most popular tourist destinations, now see the hidden gems.