Largest Cities in the World

One thing I would like to do in this blog is to occasionally post and comment on themed lists of various items related to world geography. So, to start things off in this post, the first of a series of "list" posts, I would like to list and discuss the largest cities in the world. But, when forming such a list, particularly pertaining to a geographic feature such as a city, one must ask what criteria will we take into account when classifying cities on the list. Do we just count the city itself (the city proper), the urbanized area, or the metropolitan area? Or perhaps we should form a separate list for each of those items. Various cities would most likely then appear at different points on the list. But for this post, I will list the twenty largest metropolitan areas by population (I also may come back to the post and add more lists based on different criteria as well). So, without further adieu, here we go:

Tokyo, Japan, with Mt. Fuji

Earth's twenty largest metropolitan areas by population (based on 2003 population data):
1. Tokyo, Japan - 32,450,000
2. Seoul, South Korea - 20,550,000
3. Mexico City, Mexico - 20,450,000
4. New York City, United States - 19,750,000
5. Mumbai (Bombay), India - 19,200,000
6. Jakarta, Indonesia - 18,900,000
7. Sao Paulo, Brazil - 18,850,000
8. Delhi, India - 18,600,000
9. Osaka-Kobe-Kyoto, Japan - 17,375,000
10. Shanghai, China - 16,650,000
11. Metro Manila, Philippines - 16,300,000
12. Hong Kong/Shenzhen, China - 15,800,000
13. Los Angeles, United States - 15,250,000
14. Kolkata (Calcutta), India - 15,100,000
15. Moscow, Russia - 15,000,000
16. Cairo, Egypt - 14,450,000
17. Buenos Aires, Argentina - 13,170,000
18. London, United Kingdom - 12,875,000
19. Beijing, China - 12,500,000
20. Karachi, Pakistan - 11,800,000

Sao Paulo, Brazil