Ilhabela, Brazil

With a population of just 13,538, this remote Brazilian island is hardly the tropical paradise it's marketed as. The sole access is by ferry, which can mean hours-long waits during peak season. And while the lush Atlantic forests cover 84% of the municipality, the lack of proper sewage infrastructure is an ongoing environmental headache. Tourists seeking adventure may relish the 360 waterfalls and 50 shipwreck diving sites, but the caiçara communities on the outlying islands live in near-isolation, lacking basic services. Ilhabela is best suited for the hardiest of eco-tourists, not the average sun-seeker.