Prison Island, known locally as Changuu, lies a short boat ride off Stone Town and takes its English name from a prison building constructed there in 1893 by Lloyd Mathews, the British First Minister of Zanzibar. In an unexpected turn, the prison was never actually used to hold prisoners, and its cell-like rooms instead served as a quarantine station for ships during yellow fever outbreaks.
The island at a glance
- A small coral island a short boat ride from Stone Town, Zanzibar
- Prison building constructed in 1893, though never used to hold prisoners
- Repurposed as a yellow fever quarantine station for ships approaching Stone Town
- Home to a protected colony of Aldabra giant tortoises
A history of quarantine, not incarceration
The rooms often described as prison cells actually functioned as hospital wards where ship passengers were held for observation before being cleared to enter Stone Town, making “Quarantine Island” a more accurate name than the one that stuck. The imposing fortified structure remains standing today and can be explored on a visit, alongside the island’s small beach and surrounding waters.
The Aldabra giant tortoises
Changuu is also home to a colony of Aldabra giant tortoises, a gift from the British Governor of Seychelles in 1919, with some individuals now marked with their age in blue paint on their shells and recorded at well over 190 years old. The island functions as one of a handful of places worldwide where this vulnerable species breeds successfully under protection.
Things to do
- Visiting and feeding the Aldabra giant tortoises
- Exploring the former prison and quarantine buildings
- Swimming from the island’s sandy beach
Practical information
- Reached by a short boat ride from Stone Town’s harbour
- Snorkelling here is modest compared with Mnemba Atoll or Chumbe Island due to reef wear from boat traffic
- Best visited as a half-day excursion combined with Stone Town sightseeing
Prison Island offers an easy, history-rich half-day escape from Stone Town. Offmap Safaris can build it into a Zanzibar itinerary. To start planning, visit Plan My African Safari, message us on WhatsApp at +256 701 243 304, or email [email protected]. See also our notes on health and safety and responsible travel.
