Located 5.6 km northwest of Stone Town, Unguja, Prison Island is a compact gem in the Indian Ocean, accessible as part of a Zanzibari adventure. Also known as Changuu—its Swahili name derived from a local fish species abundant in the surrounding waters—the island spans a modest length of 800 meters.

Beneath its idyllic exterior lies a darker past. Prison Island remained uninhabited until the 1860s when Majid bin Said, the first Sultan of Zanzibar, granted it to two Arab slave owners. They used the island as a detention site for rebellious slaves.

In 1893, British First Minister Lloyd Matthews acquired the island and envisioned it as the site for a prison. Although construction was completed in 1894, the facility never housed any prisoners.

By the 1920s, Prison Island took on a new purpose as a quarantine station for British territories in East Africa. The prison structures were repurposed into a hospital where patients were closely monitored for one to two weeks before being allowed to depart.

Private boats to Prison Island depart from the pier near Forodhani Gardens, a charming park along the Stone Town promenade. The sea journey to the island takes approximately 20 minutes each way, and it’s an adventure in itself. As the boat cuts through the sparkling azure waters, creating white sprays on either side, you’re sure to enjoy this brief but delightful voyage.

Before embarking on your trip to visit the tortoises, you can negotiate the fare right on the shore. There’s no need to dedicate too much time to exploring Prison Island—a couple of hours are usually enough unless you plan to take a leisurely walk along the shore or spend extra time capturing memories in the prison ruins and the tortoise park. After all, life is fleeting compared to the enduring lifespan of the Aldabra giant tortoises, so you may want to save time for Zanzibar’s other captivating attractions.

Giant tortoises

Prison Island is renowned for its thriving population of Aldabra giant tortoises. In 1919, the British governor of Seychelles gifted four tortoises to the island. These tortoises flourished, and by 1955, the population had grown to 200. However, in the latter part of the 20th century, the tortoises faced a significant decline as many were stolen and sold as pets or for their meat.

Fortunately, dedicated conservation efforts have prevented the extinction of these remarkable creatures, and their numbers are steadily recovering. Today, visitors to the island can feed the tortoises and observe their fascinating social behaviors up close.

Snorkelling

The sapphire waters surrounding Prison Island make it an excellent destination for snorkeling. Many tour packages offered by travel companies in Stone Town include snorkeling gear as part of the experience, ensuring visitors can fully enjoy the vibrant marine life.

The Zanzibar Dive Centre, based in Stone Town, is one of the most reputable tour operators in the area. By booking with us, you can relax while we handle all the arrangements for your chosen activities, ensuring a seamless and memorable experience.