Near the Tanzanian coast, around 300 km south of Dar es Salaam, the island of Kilwa Kisiwani is a UNESCO World Heritage Site. Occupied from the 9th century to the 11th century, it reached its heights in the 13th and 14th centuries. It was described by the Moroccan explorer Ibn Battouta as “one of the most beautiful cities in the world.” A former Swahili trading city, the island prospered from the trade of gold and ivory from the inland regions. The remains of its former port city cover a large part of the island. Those of its superb Great Mosque, the oldest mosque remaining on the coast of East Africa, are well worth a visit.