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

2. What inspired the design of the interior columns in the Sagrada Família?

3. To what does the name 'Big Ben' technically refer?

4. What part of the original colossal lion gate at Sigiriya still exists today?

5. Mount Fuji is classified as which type of volcano known for its symmetrical, conical shape?

6. What material covers the exterior of the Guggenheim Museum Bilbao, giving it its shimmering, scaly appearance?

7. The bronze-colored lattice wrapping the NMAAHC pays tribute to the historic craftsmanship of which group?

8. Under which Ottoman Sultan did construction of the Grand Bazaar begin?

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

10. What is the nickname for the notoriously critical fans who sit in the highest gallery of La Scala?

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

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

13. What is unique about the construction of the churches in Lalibela?

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

15. What was the primary purpose of the massive circular stone doors found in Derinkuyu?

16. What was the original 19th-century functional purpose of the Jet d'Eau?

17. What is the popular nickname for the Beijing National Stadium due to its lattice-like steel exterior?

18. What is Bangkok known as in Thai?

19. What is Wat Arun commonly known as?

20. What is the best-known floating market near Bangkok?