A short boat ride from Stone Town, Changuu Island combines giant tortoises, colonial-era history and clear water for snorkeling in an easy half-day outing.
From the Stone Town waterfront you can see a low green island on the horizon. That is Changuu, better known as Prison Island, and it makes one of the easiest and most enjoyable half-day excursions on Zanzibar.
Despite its name, the island is now best known for its colony of giant tortoises, some of them very old indeed. Add a bit of history, a sandy beach and good snorkeling nearby, and it is easy to see why most first-time visitors include it.
Quick tips
- Bring swimwear and a towel if you want to snorkel or relax on the beach.
- Carry small bills in cash for the island entry fee and drinks.
- Wear sun protection, since shade on the boat may be limited.
- Ask the keepers before feeding the tortoises.
- Combine Prison Island with a Stone Town walking tour on the same day.
A Short History of Changuu
In the nineteenth century the island was reportedly used to confine enslaved people. Later, under British rule, a prison was built there, though it is widely reported never to have housed prisoners. Instead, the island served as a quarantine station for people arriving during outbreaks of disease.
Some of the old buildings remain, and guides on the island share stories of these different chapters. It is a quiet place to reflect on Zanzibar's complicated past.
The Giant Tortoises
The tortoises are Aldabra giant tortoises, a species from the Seychelles. The first animals are said to have been a gift to Zanzibar in the early twentieth century, and the colony has been looked after on the island since. Today they live in a protected enclosure where visitors can walk among them.
Some individuals are believed to be well over a hundred years old. Keepers often provide leaves for visitors to offer, and staff will show you how to do this without harming the animals.
Visiting Responsibly
Giant tortoises are slow and placid, which can tempt people to treat them like props. Please do not sit on them, lift them or pull their heads out for photos. Follow the keepers' instructions, keep hands away from their mouths when feeding and wash or sanitize your hands afterward.
Children love this part of the visit, so take a moment beforehand to explain the rules. A calm approach also rewards you: relaxed tortoises stretch out their long necks and move about freely, which makes for far better photographs than a startled animal pulled into its shell.
Getting There and Timing
Boats leave from the Stone Town beach area and the crossing typically takes around half an hour, depending on the boat and sea conditions. A visit of two to four hours, including the crossing, is typical. An entry fee is charged on the island, separate from the boat cost, so confirm what your trip includes before setting out.
Mornings tend to be calmer on the water and cooler on land.
- Choose a boat with life jackets and some shade
- Agree the return time with the captain before leaving
- Combine with a sandbank stop for a fuller morning
Snorkeling Around the Island
The reefs near Changuu offer decent snorkeling, with colorful fish and coral in shallow water. Visibility varies with the tide and weather. Bring your own mask if you prefer a good fit, or ask whether equipment is included. Avoid standing on coral, which damages it and can cut your feet.
Frequently asked questions
Why is it called Prison Island?
A prison was built there during the colonial era, but it is widely reported never to have been used for that purpose. The island later served as a quarantine station.
How old are the tortoises on Prison Island?
Ages vary, and some of the oldest tortoises are believed to be more than a century old. Keepers on the island can tell you more about individual animals.
Is Prison Island worth visiting?
For most visitors staying in or near Stone Town, yes. It is a short, easy trip that combines wildlife, history and swimming in a single morning.
