Chumbe Island, off Zanzibar west coast
Long before "eco-tourism" became a buzzword, conservationists set aside a tiny island off Zanzibar's west coast and left it almost entirely alone. Chumbe Island Coral Park protects one of the last pristine coral reefs in East Africa, alongside a rare coral rag forest home to giant Aldabra tortoises and the elusive coconut crab. The eco-lodges here run on solar power, composting toilets and rainwater harvesting, and the island has picked up international eco-tourism awards for it. Snorkel the reef sanctuary by day, then fall asleep to nothing but the sound of waves.