Camboriú, Brazil

With a population of just 40,308, this so-called "Brazilian Dubai" is hardly the cosmopolitan oasis its skyscrapers and affluent tourists might suggest. The city's high-density development and fluctuating population of over one million in summer create persistent headaches, from overtaxed infrastructure to water quality issues. And while the subtropical climate may be mild, the threat of floods and droughts can be disruptive. This is a city geared squarely toward well-heeled tourists, not permanent residents looking for an easy life. Camboriú may be a playground for the wealthy, but for most, the hassles likely outweigh the beachside attractions.