Prison Island (Changuu), Zanzibar: Giant Tortoises, Snorkelling and How to Visit

Despite the name, the island is best known today as a gentle half-day outing. Visitors come to meet the resident giant tortoises, walk among old stone walls and swim or snorkel off a sheltered beach.

This guide explains what the trip involves, when it works best, and how to fit it around a Stone Town stay or a beach holiday on the main island.

This guide is part of our Uganda districts and towns guide. When you are ready to plan, see our Uganda safari packages or the Ameera Africa Safaris Uganda tours homepage.

What Prison Island Is

Changuu is a small island of coral rock covered in low forest and scrub, lying within sight of the Stone Town waterfront. In the nineteenth century it was developed during the Omani sultanate period, and a prison building was constructed there, although it is widely described as having been used as a quarantine station rather than as a conventional jail. The island still holds the stone remains of those buildings, which make an atmospheric backdrop for a stroll.

Today it is a protected visitor site with a small entrance arrangement, a beach, a snack area and well-kept paths. It is a very different experience from the main island beaches: compact, easy and designed for a short visit. See Zanzibar and Stone Town guide for the wider picture.

The Giant Tortoises

The tortoises are the main reason most people go. The population descends from Aldabra giant tortoises, a species native to islands in the Indian Ocean, brought to Zanzibar in earlier times. They live in a fenced enclosure and roam in a sanctuary area where staff look after them, and some are very old. Visitors can usually watch them feed on leaves and gently stroke the shells under guidance.

Treat them calmly. Do not sit on the animals, do not feed them anything other than what staff provide, and keep children close so that nobody is startled. Hatchlings are kept in a separate area to protect them. Ask your guide about the sanctuary rules on the day, as arrangements can change.

Snorkelling and Swimming

The sheltered side of the island has clear shallow water with patches of coral and small reef fish, and most boat trips include snorkelling time. It suits beginners and children because depth is modest and currents are usually mild, but conditions depend on tide and weather, and visibility varies from day to day. Early morning is usually calmest.

Wear a rash vest or reef-safe sun protection, never stand on or touch coral, and keep a safe distance from sea urchins. If you want more serious snorkelling or diving, the reefs off the north and east coasts and around Mnemba are better. See Zanzibar diving and snorkelling guide and Mnemba Island.

Getting There and Booking

Boats leave from the Stone Town waterfront area, and the crossing is short enough that it feels like a ferry ride rather than an expedition. Most visitors book through a hotel, a tour operator or a licensed boatman, and some trips pair the island with a spice tour or a walking tour of the old town. Ask what the quoted trip includes, how long you will have on the island, whether snorkel equipment is supplied and whether any entrance charges are separate. Official charges apply and are not listed here.

Choose a licensed operator with life jackets on board, and avoid hurried arrangements made with unofficial touts. See Stone Town and spice tours.

Best Time to Go

The island can be visited all year, though the sea is calmest and skies clearest in the dry months from about June to October and again from roughly January to February. During the long rains, usually March to May, some crossings may be cancelled or rough, and during the short rains in November and December showers are brief but possible. Go in the morning for cooler walking and better light for tortoise photographs.

Midday is hot and shade is limited, so bring a hat, water and sun cream. See best time for Zanzibar beaches for the wider seasonal picture.

Combining It With Other Plans

Prison Island fits neatly into a Stone Town stay of one or two nights. A common pattern is a morning boat trip, lunch back in the old town, then a stroll through the lanes and a sunset by the waterfront. Visitors based on the beaches can still make the trip as a day excursion, though it adds transfer time. Families often like it as a gentle break between beach days.

If you are weighing where to sleep, see Stone Town where to stay, and for the island as part of a longer trip see Tanzania safari and Zanzibar combination.

Practical Tips

Wear sandals you can get wet and carry a small dry bag for phones and cameras. Take cash in small notes for snacks, donations or tips, as card machines on small islands are unreliable. Modest dress is appreciated in Stone Town, even if swimwear is fine on the beach. Keep valuables to a minimum, and listen to the boat crew about landing and leaving times, because tides can limit the schedule.

Check health and vaccinations and Tanzania and Zanzibar practical guide before you travel.

Planning a Uganda safari? Send us your dates and we will build the route, permits and transport around what you want to see.

Related Tours, Guides and Resources

• Ameera Africa Safaris homepage: Uganda safaris, tours and holidays
• Uganda safari packages
• Uganda travel guide
• How to book a Uganda safari
• Plan your safari with our team