Kilwa Kisiwani sits on an island off the southern Tanzanian coast and was, for several centuries, one of the most powerful trading cities in the Indian Ocean world. It controlled the gold trade out of Great Zimbabwe via Sofala, minted its own coinage, and impressed Ibn Battuta enough that he called it one of the finest cities he had seen.
The ruins were inscribed by UNESCO as a World Heritage Site, together with the nearby island of Songo Mnara. The Great Mosque, begun in the 11th century and enlarged in the 13th, is the earliest surviving mosque of its kind on the East African coast. The Husuni Kubwa palace complex above the harbour was the largest single building in sub-Saharan Africa when it was built.
The name Kilwa is used collectively for three places: Kilwa Kisiwani, the island with the ruins; Kilwa Kivinje, a 19th-century mainland town; and Kilwa Masoko, the modern administrative centre and departure point for the island.