Stone Town was host to one of the world’s last open slave markets supplying slaves to Persia, Arabia, the Ottoman Empire, which included Bulgaria, Egypt, Greece, Hungary, Jordan, Lebanon, Israel and the Palestinian territories, Macedonia, Romania, Syria, and the north coast of Africa until it was shut down by the British in 1873. The slaves were shipped there in dhows from the mainland, crammed so tightly that many fell ill and died or were thrown overboard. Below St Monica’s guesthouse, dozens of slaves, and women and children, were imprisoned for days in crowded cellars with little air and no food or toilets. Even two minutes down there, under the low roof, the atmosphere seemed poisonously oppressive. Slaves were led outside and lined up in order of size. They were tied to a tree and whipped with a stinging branch to test their mettle. Those who did not cry or faint fetched a higher price at market. Prison Island lies about 30 min by boat from Stone Town.
The island was formerly owned by an Arab and saw use for confinement of refractory slaves. No prisoners were ever housed on the island and instead it became a quarantine station for yellow fever cases. The station was only occupied for around half of the year and the rest of the time it was a popular holiday destination. More recently, the island has become a government-owned tourist resort and houses a collection of endangered Aldabra giant tortoises which were originally a gift from the British governor of the Seychelles.