Chumbe Island
The island's ecotourism concept was the brainstorm of a German conservationist who, since the early 1990s, has succeeded in developing it as one of the world's foremost marine sanctuaries. Seven thatch bungalows with specially built roofs catch rainwater which is then funneled into bathrooms through a tank in the floor. Electricity is solar-powered, and toilets are doused in sweet-smelling compost and later cleaned. This isn't a service-oriented luxury resort (although staff look after the guests very well) but a fascinating, genuine eco-project on a pristine island where you can learn about sustainability at Chumbe, with your accommodations costs subsidising the project. Scuba diving, snorkeling, island hikes guided by expert rangers, and outrigger boat rides give you plenty to do.