AFP, I aim and hope for a good five.

#1. New York City, USA
Eugene de Salignac  Brooklyn Bridge, painters on suspenders, October 7, 1914

#2. London, UK
Zack Zhang  Bonnie Chen in 'Fabulous London' for Harper's Bazaar, China, July 2012

#3. San Fransisco, USA
George Steinmetz  Golden Gate Bridge 2012

#4. Paris, France
Joey Zanotti  En Hiver - Eiffel Tower 2011

#5. Tokyo, Japan
J.Ho  Bridal Procession, Tokyo, 2008

#6. Hong Kong
Mark Leong  Central Kowloon Housing Projects

#7. Las Vegas, USA
Yann Arthus-Bertrand  Altitude 2011

#8. Rio De Janeiro, Brazil
Christophe Simon  View of the Rocinha shantytown in Rio de Janeiro, Brazil. Since Rocinha's 'pacification' by authorities in November, several houses have been repainted in bright colours. 2011

#9. Mexico City, Mexico
Pablo López Luz  Aerial View of Mexico City XIII, Mexico, 2006

#10. Dubai, United Arab Emirates
Alexander Heilner Palm Jumeirah 2010

#11. Berlin, Germany
Unknown  Street Art Paint War, Berlin

#12. Hanoi, Vietnam

#13. (I don't think this is actually anywhere near) Beijing, China

#14. Agra, India

#15. Reykjavik, Iceland
Christopher Schoenbohm  'Steamy Bath', Iceland, Reykjavik, The Blue Lagoon 2010

#16. Shanghai, China
Viktor Lakics  Shanghai Detial 2012

#17. Actually, all of India
Anurag Kumar  Holi Celebration, India 2011

#18. Maybe also all of China
Steve McCurry

#19. Somewhere in Burma/Myanmar
Steve McCurry  Mt. Popa, Burma

#20. Rabat, Morocco
Frans Sellies  El Jadida, Cistern 2009

#21. this photo is neither Bogotá or Cartagena, Colombia
Unknown  Las Lajas Sanctuary

It fell apart towards the end, but essentially
1. New York City
2. London
3. San Francisco
4. Paris
5. Tokyo
6. Hong Kong
7. Las Vegas
8. Rio De Janeiro
9. Mexico City
10. Dubai
11. Berlin
12. Hanoi
13. Beijing
14. Agra, New Delhi, Mumbai, Goa
15. Shanghai
16. Burma/Myanmar
17. Morocco
18. Bogotá, Cartagena