Changuu Island, commonly known as Prison Island, is a small island located about 5.6 kilometres northwest of Stone town, Zanzibar. Initially, the island was used as a detention camp for rebellious slaves in the 1860s. Later, in the late 19th century, it was developed as a quarantine station for yellow fever cases. Prison That Never Was: Although named "Prison Island," the building constructed for the prison never housed any prisoners and was instead used as a quarantine station. One of the main attractions of Changuu Island is the population of Aldabra giant tortoises. These tortoises were a gift from the British governor of Seychelles in 1919, and some are over 100 years old. Conservation Efforts: The island serves as a sanctuary for these tortoises, with ongoing conservation efforts to protect and preserve the species. The island is surrounded by clear, turquoise waters and coral reefs. Visitors can enjoy beautiful views of ocean and the mainland from various points on the island.