Changuu Island, also known as Prison Island, is a tranquil haven located off the coast of Zanzibar, Tanzania. Renowned for its giant Aldabra tortoises, which were introduced in the late 19th century, the island also features historical ruins of a prison that was never used for its intended purpose. Instead, it served as a quarantine station for yellow fever patients. Visitors can explore the island's lush greenery, relax on its pristine beaches, and snorkel in the crystal-clear waters teeming with vibrant marine life. Changuu Island offers a perfect blend of history, wildlife, and natural beauty, making it an ideal day trip destination.