Prison Island (Changuu)
Zanzibar, Tanzania · Nature
About Prison Island (Changuu)
Prison Island, officially known as Changuu Island, is a scenic islet located just off the coast of Stone Town in Zanzibar. Originally built in the late nineteenth century as a quarantine station, it is now world-famous as a sanctuary for giant Aldabra tortoises. Today, travelers come to feed these magnificent reptiles, explore historic colonial ruins, and snorkel in turquoise coastal waters.
Don't miss
- Interact with and feed the Aldabra giant tortoises, some of which are well over a century old.
- Wander through the historic nineteenth-century prison ruins and quarantine station buildings.
- Snorkel the shallow fringing reef that teems with starfish and colorful tropical fish.
- Take in panoramic views of Stone Town while walking along the island's wooden jetty and white sand beach.
Plan your visit
Visit early in the morning around 8:30 AM to beat the crowds and midday heat. The dry months from June to October and December to February provide the clearest water conditions for snorkeling.
Paid entry is required for the tortoise sanctuary, plus the separate cost for the boat transfer. You can easily book a boat captain on the Stone Town beach or reserve a guided tour in advance.
Hire a traditional motorized wooden boat directly from the beachfront or port in Stone Town. The scenic ride across the channel takes approximately 20 to 30 minutes each way.
Tips for visiting
- Wear water shoes or sandals, as you will likely need to wade into shallow water to board and disembark the boat.
- Bring your own snorkeling gear or thoroughly check rented equipment from your boat captain before departing.
- Carry cash in local currency or US dollars to pay the island sanctuary entrance fee directly.
- Pack reef-safe sunscreen, sunglasses, and plenty of water, as shade is limited on the paths and beach.
- Respect the tortoises by avoiding sudden movements, never sitting on them, and feeding them only provided greens.
Prison Island (Changuu) FAQ
Were prisoners ever actually kept on Prison Island?
Despite its name, the island was never actually used to house convicted criminals. The British authorities repurposed the newly built facility into a quarantine station for yellow fever outbreaks to protect the mainland. Today, the preserved buildings offer a fascinating glimpse into this colonial-era history.
How did the giant Aldabra tortoises get here?
The tortoises were originally a gift from the British Governor of Seychelles to the Sultan of Zanzibar in 1919. The initial group of four flourished in the island's sheltered habitat, multiplying over the decades into the large protected colony seen today. Several of the oldest tortoises have their estimated age painted on their shells.
Is the boat trip safe for young children and families?
Yes, it is a very family-friendly excursion that children of all ages typically love. Make sure your boat operator provides appropriately sized life jackets for everyone on board before setting off. On windy days, the ocean can be slightly choppy, so morning crossings are usually smoother.
Can you buy food and drinks on the island?
There is a small historic hotel restaurant and a bar on the island offering refreshments and meals, but prices are higher than on the mainland. It is wise to bring your own drinking water and light snacks for the trip. You can also easily head back to Stone Town in time for lunch.
More things to do in Zanzibar
Stone Town Neighborhood
Wander through a UNESCO-listed maze of narrow alleys, carved wooden doors, and vibrant bazaars.
Jozani Chwaka Bay National Park Nature
Spot rare and endemic red colobus monkeys swinging through lush indigenous mahogany forests.
Spice Farm Tour Activity
Discover how vanilla, cloves, nutmeg, and cinnamon are grown and harvested on local farms.
Forodhani Gardens Night Market Food
Feast on street food delights like Zanzibar pizza and fresh seafood skewers by the oceanfront.
Mnemba Atoll Snorkeling Activity
Explore pristine coral reefs teeming with tropical fish and frequent wild dolphin sightings.
The Rock Restaurant Food
Dine at a world-famous oceanfront eatery perched on an isolated coral outcrop in Michamvi.
Nungwi Beach Landmark
Relax on powder-white sands that allow all-day swimming unhindered by extreme tidal drops.
AI-written guide, last updated 2026-10-09. Check opening times and ticket prices on the official website before you go. Photos: Jonas-Thoren, rmcclurg on Pixabay.