A luxury version of a Robinson Crusoe experience is how this Six Senses hotel bills itself. Featuring roof decks for stargazing and outdoor bathtubs for bathing under the stars, the villas seem to merge with the pristine jungle and sandbanks of Olhuveli island. A percentage of total resort revenues, 50 percent of water sales and 100 percent of soft-toy sales are allocated to projects benefitting the environment and local communities. More than 500 sea turtles and 135 mantas are being monitored and protected by the marine team on the island, and coral and seagrass are also regularly surveyed and safeguarded. Learn about it all at the on-site Earth Lab, or take a sustainability tour – when you’re not kicking back at the bird’s-nest spa, of course.