Editors' pick: Originally published May 19.

For a certain type of person, life as an expat is a dream come true. It comes with foreign adventure, interesting food and the occasional thrill.

Of course, it's not all fun and games. Life abroad can have its downsides too. Yet for those who love it, the expat lifestyle can be addicting. They have a hard time settling back down into a community that doesn't span the globe. They're the people who spend cocktail parties dreaming of dingy rooftop bars and would happily swap fine loafers for a nice, worn pair of sandals.

The catch, as with so many things in life, is money. Finding and funding that expat adventure isn't easy, and work isn't always the worst of it. Costs of living can bite back, too.

Although moving overseas often means embracing a far cheaper cost of living, that's not always the case. Sometimes life overseas can get expensive, like in these 12 cities ranked the most expensive expat destinations in the world by the consulting firm Mercer.

12. London, United Kingdom

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Between the strong pound and the expenses of one of the world's most desirable cities, this is not a home for the financially faint of heart.

Which is why it does hold firm as the world's 12th most expensive expat destination.

Sharing the heartache with its sister city across the pond, one of London's most crushing expenses is housing. They can be, in a word, brutal. With apartments costing hundreds of pounds per week and the average home purchase up to £500,000, it's almost impossible to find an affordable place to live in the heart of the United Kingdom.

On the other hand, the city makes up for it by offering some of the best beer in the world.