There are many islands surrounding Zanzibar of which prison Island is the most popular to visit. It is reached by boat and is famous for the giant tortoises and peacocks, which can be seen among the ruins in the courtyard. The giant tortoise, the most popular attraction on the island can reach a century old and some over a metre tall. The island is fringed with a beautiful coral reef, ideal for snorkelling, and has a lovely white beach for sunbathing.

Prison Island was once the site of a gaol for misbehaving slaves. A wealthy slave owner who used to send slaves to the island for discipline was the first owner. After the abolition of slavery the island was inhabited by a British General and later used as a quarantine station. The quarantine housing is still there as well as a natural lagoon and a small beach and restaurant.