Istanbul[b] (/ˌɪstænˈbʊl/ IST-an-BUUL,[7][8] US also /ˈɪstænbʊl/ IST-an-buul; Turkish: İstanbul [isˈtanbuɫ] (listen)) is the largest city in Turkey, serving as the country's economic, cultural and historic hub. The city straddles the Bosporus strait, lying in both Europe and Asia, and has a population of over 15 million residents, comprising 19% of the population of Turkey.[4] Istanbul is the most populous European city,[c] and the world's 15th-largest city.