Izmir, historically Smyrna, is Turkey's third most populous city and the country's largest port after Istanbul. It is located along the outlying waters of the Gulf of Izmir, by the Aegean Sea. It is the seat of Izmir Province, which has an area of 7350 km2. The city of Izmir is composed of ten metropolitan districts, each with its own distinct features and temperament. The total area of the nine districts is 855 km2 (330 sq mi) and together these districts constitute the area of the Izmir Metropolitan Municipality headed by the Mayor of İzmir.