İzmit (Greek:Νικομήδεια, Nikomedeia), traditionally called in English Ismid, is a city in Turkey, the administrative center of the Kocaeli Province as well as the Metropolitan Municipality. It is located at the Gulf of İzmit in the Sea of Marmara, about 100 km (62 mi) east of Istanbul, on the northwestern part of Anatolia. The city center has a population of 300,611 (2011 census). The population of the province (including rural areas) is 1,459,772. (Unlike other provinces in Turkey, apart from Istanbul, the whole province is included within the municipality of the metropolitan center.)