Kadıköy, is a large, populous, and cosmopolitan district in the Asian side of Istanbul, Turkey, on the northern shore of the Sea of Marmara, facing the historic city centre on the European side of the Bosporus. Kadıköy is also the name of the most prominent neighbourhood of the district, a residential and commercial area that, with its numerous bars, cinemas and bookshops, is the cultural centre of the Anatolian side of Istanbul. Kadıköy became a district in 1928 when it was separated from Üsküdar district. The neighbourhoods of İçerenköy, Bostancı and Suadiye were also separated from the district of Kartal in the same year, and eventually joined the newly formed district of Kadıköy. Its neighbouring districts are Üsküdar to the northwest, Ataşehir to the northeast, Maltepe to the southeast, and Kartal beyond Maltepe. The population of Kadıköy district, according to the 2007 census, is 509,282.
