20. Los Angeles

Los Angeles, Calif. ranks 20 in the MasterCard Global Destination Cities Index. It is expected to attract 4.84 million international visitors in 2013. (Credit: Joe Klamar/AFP/Getty Images)

With summer approaching, thoughts of vacation become inevitable. Should one flee the heat by heading to some cooler clime? Or perhaps one should head to beach and luxuriate in the sun (but be careful!).

Well, if current travel trends persist, you can follow the millions who are heading to 2013's most popular tourist destination, a spot known for its tropical climate and beautiful beaches: Thailand. That's right, Thailand's capital city of Bangkok will surpass London as the world's most popular tourist destination of 2013, according to a forecast issued this week.

View the slideshow above to see which cities made theMasterCard Global Destination Cities Index of the world's most popular destinations for international visitors. Did your favorite spot make the list?

Bangkok, which is expected to attract 15.98 million international visitors this year,beat out 2012 leader London by a slim margin, but it has demonstrated astonishing growth rates of better than 18 percent in 2011 and 2012,with a further 9.8 percent growth in 2013, according to the Global Destination Cities Index.

Theindex also shows the emergence of Asian cities as top destinations by international visitor arrivals. The Thai capital is one of eight growing hubs in the Asia-Pacific region ranked in the top 20.

The findings of the report, including visitors and passenger growth forecasts for 2013, are based on an analysisof a global network of 132 destination cities. The report then ranks them in terms of the number of their total international visitor arrivals and the cross-border spending by these same visitors in the destination cities.

The index has been compiled by MasterCard since 2010, and this is the first time an Asian city has topped the rankings.

Only two U.S. cities made the top 20: New York (at No. 5 with an expected 11.5 million international visitors in 2013) and Los Angeles (at No. 20 with an expected 4.8 million).

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