This small island is just 3.5 miles (6 km) from Stone Town, and was the site of a prison complex built in the late 1800s during British colonial rule. The prison was never used, and the island is now home to a tortoise sanctuary.
From Stone Town, take the 20-minute ride northwest to arrive at Prison Island. Once there, enjoy some great snorkeling before seeing the island's tortoises up close. If you are feeling active, feel free to explore one of the hiking trails, or go for a refreshing swim in the warm and crystal clear waters. Soak up some of the tropical sun on the white sandy beach and enjoy this secluded spot before taking the boat back to Stone Town.
Also you can combine prison island trip with stone town.