Gaziosmanpaşa (pronounced [ɡaːziosˈmanpaʃa]; old name: Taşlıtarla) is an impoverished working class municipality (belediye) and district of Istanbul, Turkey, on its European side. With a population of 400,000 plus, it is one of the most populous districts. In 2009 Gaziosmanpaşa district was divided into three districts: Gaziosmanpaşa, the central; Sultangazi, the northern part; and Arnavutköy, the northernmost part.