Boat trip Stone town to Prison Island Prison Island, also known as Changuu Island, is located in the western part of Zanzibar Island, near Stone Town. It takes about 25 minutes by local boat from Stone Town beach. The island’s main attraction is its popular giant tortoises, which can live up to 200 years old. On this tour, you will have the chance to explore and learn about the history of these magnificent creatures and also about Prison Island itself. You will be with our knowledgeable local guide who will explain each area of interest. Besides being a place where you can see the giant tortoises, it is also a perfect destination for swimming and relaxing on the beach. So after all the information about the island, you will have time to swim and relax on the beach.