A Day Among Giants: Visiting Changuu Island (Prison Island) off Stone Town
A quick boat ride from Stone Town offers tortoises, tide-swept sandbanks and easy snorkeling — all in a half-day escape.
You step off the dhow as the hull bumps a narrow wooden jetty and the Indian Ocean smells like hot salt, coconut oil and a far-off market. The day-trippers fold up their umbrellas, camera straps click into place and the island’s low profile unfolds — scrubby casuarina trees, a cluster of historic buildings, and the unmistakable lumbering shapes of Aldabra giant tortoises moving like small, gray boulders with heads. This is Changuu Island, called Prison Island for the Victorian-era quarantine buildings that once housed would-be prisoners and the sick. It’s small, immediate and quietly theatrical: a compact marine microcosm that layers colonial history, conservation, and easy coastal adventure in a single half-day outing from Stone Town.
Trail Wisdom
Time your tide
Visit mid to high tide for snorkeling and low tide to walk out to exposed sandbanks; check local tide charts before booking.
Bring reef-safe sunscreen
The coral gardens are fragile—use reef-safe sunscreen and avoid lotions with oxybenzone to protect marine life.
Carry small change
Vendors and boat operators often prefer cash (Tanzanian shillings) for snacks, entrance fees and tips.
Respect the tortoises
Follow guides’ rules on feeding and handling—do not chase or lift animals and avoid flash photography at close range.
Local Knowledge
Hidden Gems
- •Walk the island loop at low crowd hours for photographic angles of colonial ruins and lone baobab silhouettes.
- •Combine a morning Prison Island trip with a late-afternoon walk through Stone Town’s Forodhani Gardens for fresh seafood and sunset views.
Wildlife
Aldabra giant tortoise, Reef fish such as parrotfish and wrasse
Conservation Note
The tortoise colony is maintained by conservation caretakers; visitors are encouraged to support entrance fees and local programs that fund animal care and reef protection.
Changuu was used as a quarantine station and brief prison in the late 1800s; its colonial buildings and walls are relics of Zanzibar’s role in Indian Ocean trade and health control.
Seasonal Guide
spring
Best for: calmer seas, fewer crowds
Challenges: intermittent rains, murkier water after storms
Spring (March–May) brings the long rains early; expect occasional showers but good wildlife viewing between storms.
summer
Best for: dry weather, excellent snorkeling visibility
Challenges: higher visitor numbers, stronger sun
The dry months (June–October) are the most popular — warm water and clear visibility make snorkeling optimal.
fall
Best for: lower prices, pleasant temperatures
Challenges: short rainy periods, variable sea clarity
Short rains begin in late October/November; early fall can still be fine, with fewer tour groups and comfortable weather.
winter
Best for: milder temperatures, birdwatching
Challenges: occasional storms, some operators reduce runs
December–February is hot and humid with intermittent storms; plan around weather and book reputable operators.
Photographer's Notes
What to Bring
Snorkel mask and fins
Bringing your own ensures fit and hygiene for short reef swims off the island.
Reef-safe sunscreenEssential
Protects both your skin and the coral ecosystems around Changuu and nearby sandbanks.
Water shoesEssential
Useful for walking on rocky reef, jettys and the island’s compacted coral sand.
Light sun layer & hatEssential
Thin long-sleeve and wide-brim hat for midday sun and wind protection on exposed sandbanks.
Common Questions
How long is the boat ride from Stone Town to Changuu Island?
Most boats take about 20–30 minutes from Stone Town jetties, depending on sea conditions and the specific landing point.
Can I feed or touch the giant tortoises?
Feeding is allowed in a controlled manner by caretakers; follow guide instructions and avoid rough handling to protect the animals.
Is snorkeling available at Prison Island?
Yes — many tours stop for snorkeling near the island or combine the visit with Nakupenda Sandbank for clearer snorkeling and swimming.
Are there restrooms and food on the island?
Basic facilities and small vendors are on the island; bring water and cash for purchases, though some tours include lunch.
Is the island suitable for children or older travelers?
Yes. The island is walkable with short distances and gentle terrain, but consider sun exposure and boat motion for sensitive travelers.
Do I need to book a guided tour or can I go independently?
You can visit independently by hiring a boat at the Stone Town jetties, but guided tours often include context, entrance fees and combined stops like Nakupenda.
What to Pack
snorkel mask (better fit & hygiene), reef-safe sunscreen (protect reef), water shoes (reef/jetty walking), cash in small denominations (vendors & tips)
Did You Know
Changuu's giant tortoises were brought from Aldabra (Seychelles) in the late 19th century and some individuals on the island are over a hundred years old—part of a long-standing conservation story.
Quick Travel Tips
book morning departures to avoid midday heat; bring reef-safe sunscreen and water shoes; carry local currency for small purchases; combine the trip with Stone Town to maximize your day
Local Flavor
After your island visit, return to Stone Town for pilau or grilled seafood at Forodhani Gardens, sip spiced coffee, and wander alleys lined with carved doors—Zanzibar’s Swahili culture is best experienced in food, music and market chatter.
Logistics Snapshot
From Stone Town: 20–30 minute boat; visit duration 2–4 hours; entrance fee supports conservation; basic vendors on-site; no overnight stays; best clarity June–October.
Sustainability Note
Choose small-boat operators that follow no-touch wildlife policies, use reef-safe sunscreen, and support local conservation fees that help maintain the tortoise colony and reef health.