A Jewel of Zanzibar

Discovering Prison Island

Prison Island, also known as Changuu Island, is one of the most fascinating and historically rich destinations in Zanzibar. Located just 5.6 kilometers northwest of Stone Town, the island’s story is a tapestry of history, wildlife, and natural beauty. This article delves into the captivating history of Prison Island, its stunning natural attractions, and the vibrant wildlife that calls it home, offering a vivid exploration of why this island is a must-visit destination.

A Brief History of Prison Island

From Slave Holding to Quarantine

Prison Island’s history is steeped in the darker chapters of Zanzibar’s past. In the late 19th century, the island was used by Arab slave traders as a holding pen for slaves. Captured individuals were temporarily held on the island before being shipped off to markets around the world.

In 1893, the British purchased the island and built a prison. However, it never housed criminals. Instead, the structure was repurposed as a quarantine station for those with yellow fever. The island’s isolation made it an ideal location for preventing the spread of disease to the mainland.

The Quarantine Station

The quarantine station remained operational until the mid-20th century, playing a crucial role during various outbreaks. During this period, the island was equipped with medical facilities and staff to care for and contain those affected by infectious diseases. This aspect of its history adds a layer of medical significance to the island, making it a point of interest for those fascinated by the history of medicine and public health.

The Tortoise Sanctuary

The Aldabra Giant Tortoises

Today, one of the main attractions of Prison Island is the Aldabra giant tortoise sanctuary. These tortoises are not native to Zanzibar; they were gifted by the British governor of the Seychelles in the early 20th century. Over the years, the population has flourished, and the island is now home to one of the largest colonies of Aldabra giant tortoises in the world.

A Close Encounter

Visitors to the island are often amazed by the opportunity to interact with these gentle giants. The tortoises, some of which are over 100 years old, roam freely in a protected area. Weighing up to 250 kilograms, these creatures move slowly, embodying the passage of time and resilience. Tourists can feed the tortoises and observe them in a natural setting, creating memorable and educational experiences.

Natural Beauty and Marine Life

Pristine Beaches

Prison Island is encircled by pristine beaches that offer stunning views of the turquoise waters of the Indian Ocean. The white sandy shores are perfect for sunbathing, swimming, and enjoying the tropical climate. The tranquility of the island makes it an ideal getaway from the bustling Stone Town.

Coral Reefs and Snorkeling

The waters around Prison Island are rich with coral reefs, making it a popular spot for snorkeling and diving. The vibrant marine life includes colorful fish, sea urchins, and an array of corals. Snorkeling in these waters provides a window into the underwater world, where visitors can witness the delicate balance of the marine ecosystem.

Flora and Fauna

Beyond the beaches and reefs, Prison Island boasts lush vegetation, including a variety of tropical plants and trees. The island is also a haven for birdwatchers, with numerous species of birds nesting in its trees. This biodiversity adds to the island’s charm, making it a paradise for nature enthusiasts.

Exploring the Ruins

The Historical Prison

The prison building itself, though never used for its intended purpose, stands as a historical monument. Walking through its corridors, visitors can imagine the lives of those who were quarantined here. The crumbling walls and rusting gates evoke a sense of history, providing a stark contrast to the island’s natural beauty.

Guided Tours

Guided tours are available, offering insights into the island’s multifaceted history. Knowledgeable guides narrate the stories of the island’s past, from its role in the slave trade to its transformation into a quarantine station and eventually a wildlife sanctuary. These tours enrich the visitor experience by adding context to the scenic beauty.

Conservation Efforts

Protecting the Tortoises

Significant efforts are underway to protect and conserve the Aldabra giant tortoises. The Zanzibar government, along with various non-governmental organizations, is committed to ensuring the health and growth of the tortoise population. Conservation programs focus on habitat preservation, medical care, and breeding initiatives.

Sustainable Tourism

Sustainable tourism practices are encouraged on the island to minimize environmental impact. Visitors are educated about the importance of preserving the natural and historical heritage of Prison Island. Eco-friendly practices, such as waste management and controlled visitor numbers, are implemented to maintain the island’s pristine condition.

Visiting Prison Island

How to Get There

Prison Island is easily accessible by a short boat ride from Stone Town. Several tour operators offer day trips that include transportation, guided tours, and sometimes snorkeling gear. The boat ride itself is a scenic journey, offering panoramic views of the ocean and Stone Town.

What to Bring

Visitors are advised to bring essentials such as sunscreen, hats, comfortable walking shoes, and swimwear. Snorkeling enthusiasts should also bring their gear, though it is often available for rent. A camera is a must to capture the stunning landscapes and the unforgettable encounters with the tortoises.


Prison Island is a microcosm of Zanzibar’s rich history, natural beauty, and commitment to conservation. Whether you are a history buff, a nature lover, or simply seeking a serene escape, the island offers something for everyone. Its story, from a dark past to a beacon of conservation, is a testament to the resilience and beauty of nature and humanity. A visit to Prison Island is not just a trip to a beautiful location but a journey through time and a step towards understanding and preserving our world’s delicate ecosystems.


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