Prison Island Zanzibar: Discover Giant Tortoises and a Remarkable Island History

Prison Island Zanzibar is one of the island’s most popular half-day excursions, combining fascinating history, endangered Aldabra giant tortoises, beautiful beaches, and excellent snorkelling only a short boat ride from Stone Town. It offers visitors a unique opportunity to experience both Zanzibar’s cultural heritage and its natural beauty in a single trip.

Just a few kilometres offshore lies Changuu Island, better known as Prison Island.

Despite its name, the island was never used as a functioning prison for criminals.

Instead, its history includes quarantine facilities, colonial administration, and today, one of East Africa’s most famous conservation success stories.

Visitors come not only to learn about the island’s past but also to meet the enormous Aldabra giant tortoises that have lived here for more than a century.

Many Tanzania travellers include Prison Island Zanzibar after completing a safari, making it an easy addition to a stay in Stone Town before relaxing on Zanzibar’s spectacular beaches.

At Odysseys From Africa, we often recommend this excursion because it combines history, wildlife, marine experiences, and breathtaking coastal scenery in just a few hours.

Where Is Prison Island Zanzibar?

Prison Island Zanzibar is located approximately 5.5 kilometres northwest of Stone Town and can be reached by traditional wooden boat in around 20 to 30 minutes.

The island is officially known as Changuu Island.

Today it forms one of Zanzibar’s most visited historical and ecological attractions.

Most visitors depart directly from the Stone Town waterfront.

The short journey across the Indian Ocean provides beautiful views of:

• Stone Town skyline.
• Traditional dhows.
• Turquoise waters.
• Coral reefs.
• Small surrounding islands.

Because of its proximity to Stone Town, Prison Island is ideal for travellers with limited time.

It can easily be combined with a walking tour of the UNESCO-listed old town.

The Fascinating History Behind Prison Island Zanzibar

Prison Island Zanzibar has a far more complex history than its name suggests, evolving from a place intended for detention into a quarantine station before becoming one of Zanzibar’s leading tourist attractions.

Originally, the island was intended to serve as a prison during the late nineteenth century.

However, the prison was never used for housing convicted criminals.

Instead, colonial authorities converted many of the buildings into a quarantine station for people arriving in Zanzibar who were suspected of carrying infectious diseases.

Today, visitors can still explore many of these historic structures.

Walking through the preserved buildings offers insight into Zanzibar’s colonial history and its role as an important Indian Ocean trading centre.

The restored architecture remains one of the island’s biggest attractions.

Meet the Famous Aldabra Giant Tortoises

One of the biggest reasons visitors choose Prison Island Zanzibar is the opportunity to encounter the island’s remarkable Aldabra giant tortoises.

These impressive reptiles were originally gifted to Zanzibar by the Seychelles during the late nineteenth century.

Today, the population has grown through careful conservation.

Some tortoises are estimated to be well over 100 years old.

Walking among these gentle giants is a memorable experience.

Visitors often enjoy observing:

• Massive shells.
• Slow graceful movements.
• Feeding behaviour.
• Young tortoises in protected areas.

The conservation programme has helped secure the future of this endangered species while educating visitors about wildlife protection.

Why the Giant Tortoises Are So Special

The Aldabra giant tortoises found on Prison Island Zanzibar are among the largest tortoise species in the world and represent one of the island’s greatest conservation achievements.

Adult tortoises can weigh more than 250 kilograms.

Their remarkable lifespan often exceeds 100 years.

Some individuals may live considerably longer under ideal conditions.

These extraordinary reptiles offer visitors a rare opportunity to observe animals that have survived for generations.

Guides explain:

• Their history.
• Conservation efforts.
• Feeding habits.
• Life cycle.

Meeting these gentle giants is often the highlight of visiting Prison Island.

Snorkelling Around Prison Island

Prison Island Zanzibar is not only famous for history and tortoises but also for its excellent snorkelling opportunities in the surrounding coral reefs.

The warm Indian Ocean waters provide impressive visibility throughout much of the year.

Visitors frequently encounter:

• Colourful reef fish.
• Coral gardens.
• Sea stars.
• Reef invertebrates.
• Occasionally sea turtles.

Many half-day excursions include snorkelling equipment as part of the tour.

The calm conditions make the experience suitable for beginners as well as experienced snorkellers.

A Perfect Half-Day Trip From Stone Town

One of the greatest advantages of Prison Island Zanzibar is its accessibility.

Unlike longer island excursions, Prison Island requires only a few hours.

This allows travellers to combine several experiences in one day.

Popular combinations include:

• Stone Town walking tour.
• Spice farm visit.
• Sunset dhow cruise.
• Local seafood dinner.

Visitors staying in Stone Town can easily return by early afternoon.

This flexibility makes Prison Island one of Zanzibar’s most convenient excursions.

Combining Prison Island With a Tanzania Safari

Prison Island Zanzibar is an excellent addition to any Tanzania holiday, particularly after a wildlife safari across the mainland.

Many travellers combine Zanzibar with visits to:

• Serengeti National Park.
• Ngorongoro Conservation Area.
• Tarangire National Park.
• Nyerere National Park.
• Ruaha National Park.

Our Tanzania Explorer itinerary can be customised to include Stone Town, Prison Island, and several relaxing days on Zanzibar’s beautiful beaches.

Travellers exploring northern Tanzania may also enjoy our Best of Northern Tanzania itinerary before flying to Zanzibar.

For practical advice before your holiday, visit our Travel Information page for guidance on visas, flights, packing, and travel planning.