This tiny island, just a 20-minute boat ride from Stone Town, was once a prison and a quarantine location. Now it's a tropical paradise that's home to the giant Aldabra tortoise (you can visit the tortoises for a small fee), the duiker antelope, and a variety of birds and butterflies. There's also decent swimming and snorkeling, and a hotel and restaurant. Note that 70% of the island is private property and thus inaccessible. You can visit Changu Island on a tour, or arrange transport with a fisherman on the beach outside Archipelago's for a much cheaper price. There's no entry fee for the island itself.
5.6 km (3.5 miles) north-west of the main island of Zanzibar, Zanzibar, Tanzania