Prison Island (Changuu Island) is one of Zanzibar’s most popular half-day excursions, located about 5–6 km (a 20–30 min boat ride) northwest of Stone Town. Despite its name, it was never really used as a prison for people but has a fascinating history and some unique wildlife.
- Built in the 1860s by a slave trader to confine rebellious enslaved people.
- Later taken over by the British, who planned to use it as a prison—but it was mainly used as a quarantine station for yellow fever cases arriving in Zanzibar.
- You can still see the old prison/quarantine ruins on the island.
- Aldabra Giant Tortoises: The island is home to a sanctuary with tortoises originally gifted from the Seychelles in the 1910s. Some are over 150 years old.