Istanbul Province (Turkish: İstanbul ili) is a province located in north-west Turkey. It has an area of 5,343.02 km² and a population of 13,854,740. It is surrounded by the provinces of Tekirdağ to the west, Kocaeli to the east, the Black Sea to the northern part and the Sea of Marmara to the south. The Bosphorus (Boğaziçi) Strait divides the province in two parts: the European side and the Asian side.