1. The Great Wall of China was primarily built to protect against invasions from which group?

2. What is the name of the narrow, 1.2-kilometer-long gorge that serves as the main entrance to Petra?

3. For which Pharaoh was the Great Pyramid of Giza built?

4. What distinguishes the Blue Mosque's exterior from most other Ottoman mosques built at the time?

5. Which American theme park landmark was famously inspired by Neuschwanstein Castle?

6. What does the name 'Teotihuacan' mean in the Nahuatl language used by the Aztecs?

7. The Statue of Unity depicts which Indian leader known as the 'Iron Man of India'?

8. Which river is responsible for the erosion that created the Grand Canyon?

9. Approximately how many times is the CN Tower struck by lightning each year?

10. What is unique about the 'The Loupe' floor at the top of the Space Needle?

11. What is unique about Djemaa el-Fna's UNESCO recognition?

12. The Clementinum Library is a world-renowned example of which architectural and artistic style?

13. What lies directly beneath the vault of the Arc de Triomphe?

14. What is the popular nickname of the Woolworth Building, referring to its religious-style architecture?

15. What natural barrier made escaping from Alcatraz nearly impossible for inmates?

16. According to legend, what animal must remain at the Tower of London to prevent the fall of the Kingdom?

17. How did the Roman army finally gain access to the fortress of Masada during the siege?

18. What mineral forms the giant crystals found in the Naica Mine?

19. The superconducting magnets in the LHC are cooled to a temperature colder than what?

20. What is the climate in Bangkok generally classified as?