Introduction ; Prison Island Zanzibar Prison Island Zanzibar — also known as Changuu Island  — is one of the most iconic excursions in the Zanzibar archipelago. Just 20–30 minutes by boat from Stone Town, the island is a powerful blend of history, wildlife, and turquoise-lit tropical beauty. It is home to Zanzibar’s famous giant Aldabra tortoises, some more than 150 years old, moving slowly under palm trees with ancient, unhurried grace. The coastline glows with bright blue