Prison Island Zanzibar: tortoises, the prison that never opened and what it costs

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Last checked: October 2026.

Prison Island, Zanzibar, is where most people meet their first giant tortoise, and the tortoises are worth the boat ride: an animal the size of a coffee table, descended from animals that arrived in 1919, lifting its head to look at you with something close to interest. But Changuu has had more lives than the tortoises. It has been a holding place for enslaved people, a prison that never opened, a quarantine station and now a small hotel on government land. The tortoises arrived as a gift. Go for them, stay for the history, and keep your hands to yourself.

The detail

The history, plainly. In the 1860s the Sultan of Zanzibar, Majid bin Said, gave the island to two Arab merchants, who used it to confine enslaved people considered rebellious before they were shipped on or sold. Some accounts describe it as a sale rather than a gift. In 1893 the British First Minister, Lloyd Mathews, bought the island and built a prison; it was finished in 1894 and never housed a single prisoner. The buildings became a quarantine station instead, and in 1923 the island was renamed Quarantine Island, with passengers held for one to two weeks before being allowed on. Sources differ on why: Wikipedia names yellow fever as the main disease monitored, while the historian Sarah Longair (University of Leicester) dates the quarantine to the plague outbreak in India in 1898. Both were threats to a busy port. The arched cell block and the old hospital are still there to walk through.

The tortoises. In 1919 the British governor of the Seychelles sent four Aldabra giant tortoises to Zanzibar as a gift. They bred; by 1955 there were around 200. Then theft and trade stripped the colony to seven animals by 1996, when a breeding programme and a fenced sanctuary were set up. By 2000 the count was 17 adults, 50 juveniles and 90 hatchlings. We could not find a published count for today, and the age of the oldest animals is a matter of estimate rather than record, so treat any figure you hear on the island as approximate. Many of the tortoises carry a painted number on the shell.

Touching and feeding: our view. The sanctuary lets visitors in among the animals, and keepers hand out leaves to feed them. It is a managed attraction rather than a wild encounter, and an animal that is handled by visitor after visitor deserves restraint. Feed only what the keepers give you, let the tortoise come to the leaf rather than pushing it at its face, do not stroke the head or neck, never sit on or lean against a shell, and keep children at arm's length from the hatchlings. If the enclosure is already crowded, wait or walk on; the fence gives a clearer view than the scrum.

The boat and the fees. Boats leave from the Forodhani seafront in Stone Town; the crossing is about 5.6 kilometres and takes roughly 20 to 30 minutes in a small motorboat, longer and wetter if the sea is up. Two charges sit on top of the boat. Published sources report the island entry fee anywhere from US$4 to US$12 per person; they disagree, and the gate price is unknown. Separately, Changuu falls within the Changuu-Bawe marine conservation area, where Zanzibar has charged a conservation fee of US$10 per adult and US$5 per child aged 5 to 15, per day, since 1 September 2025. Sources quote different totals, and it is not always clear whether a boat price includes either fee, so ask what is included. Hotel-arranged boats and a private skipper from Forodhani are the two usual ways to go; the beach touts offering the lowest price are the least reliable about timings and return.

Snorkelling and swimming. There is a narrow beach on the Stone Town side and a modest reef in shallow water off it. It is a pleasant swim and an easy first snorkel for a confident child, but visibility is variable and the coral has seen better decades. If snorkelling is the point of your day, Chumbe Island or Mnemba are in a different league.

Timing. Go first thing: the sanctuary is calmer, the light is good and the water is generally calmer in the morning, though conditions vary with the wind. By late morning in high season more boats tend to arrive from Stone Town and the resorts. Allow about two to three hours door to door; many people pair the island with a Stone Town walk the same morning.

Key facts

Verdict: worth a morning if you are in Stone Town with children or an interest in history; skip it if you only want reef.

Planning it with Nobu

We will tell you what Changuu is and is not: a short, worthwhile morning with remarkable animals and a difficult history, rather than a wildlife experience or a serious snorkel. A travel designer can time it early with a private boat, so you reach the sanctuary before it fills. The history is told in full, including the part about enslaved people, because your Africa, beautifully told has to include the hard chapters.

Is it right for you?

You are spending a night or two in Stone Town on your holiday and want a half-morning out on the water; you are travelling with children who will remember a giant tortoise for life; you are interested in how the island's colonial and slave-trade past overlap in one small place. Less ideal if you dislike managed animal attractions (the sanctuary is exactly that, and you may prefer to watch from the fence), if small boats in a chop make you unwell, or if you only want the snorkelling.

Journeys to consider

• Shores of Zanzibar — a Stone Town morning on the water before the coast. → Shores of Zanzibar journey
• Southern Safari & Spice — the island chapter after Tanzania's southern parks. → Southern Safari & Spice journey