Irresistible cities: World's 25 top tourism destinations

(CNN)Still one of the world's most vibrant cities despite astronomical living costs, it's no surprise London is the world's second most visited destination.

So what's the first?
The emphatic answer, says market researcher Euromonitor International, is Hong Kong.
Attracting an impressive 27.77 million international tourists in the space of a year, the Asian city outstripped London's popularity to the tune of 10 million people.
The influx, chiefly accounted for by mainland Chinese visitors, kept Hong Kong at the forefront of Euromonitor's annual Top 100 City Destinations survey for the fifth year in succession.
London, which last crowned the list in 2009, pulled in a mere 17.38 million, just ahead of Singapore at 17.09 million.
    Euromonitor's list is compiled from data from 57 "core" countries, using national statistics and info from airports, hotels and other tourism industry sources.
    The company says the latest figures, from 2014, show geopolitical tensions and successful marketing campaigns swaying tourist decisions.

    Fluctuating fortunes

    But despite fluctuating fortunes for some key destinations, it says tourism remains an upward trend with all but a few cities improving on visitor numbers.
    That said, Euromonitor warns of interesting times ahead for some of the main players.
    It says Hong Kong's reliance on Chinese tourists is a weakness as their increasing affluence takes them further afield -- a situation likely to be exacerbated by recent protests there against mainland Chinese travelers.
    London's expensive reputation and the fact that its airports are nearing capacity could also see it losing out to European rivals, Euromonitor says.
    As for Singapore, "limited natural attractions" and a reputation as a business rather than leisure destination could see it struggle to "remain relevant" against low-cost alternatives like Thailand.
    Istanbul, currently ranked ninth, is identified by Euromonitor as "one to watch."
    It says the city could build on a year-on-year increase of 13.2% although the emergent threat of ISIS could prove challenging.
    Click through the above gallery to see the top 25 most visited cities.