Istanbul (Turkish: İstanbul) is the largest city in Turkey, forming the country’s economic, cultural, and historical heart. With a population of 13.5 million, the city is at the center of the second-largest metropolitan area in Europe and among the world’s largest cities by population within city limits.[Istanbul's vast area of 5,343 square kilometers (2,063 sq mi) is coterminous with Istanbul Province, of which the city is considered capital.[ Straddling the Bosphorus—one of the world's busiest waterways—in northwestern Turkey, between the Sea of Marmara and the Black Sea, Istanbul is a transcontinental city, with one third of its population living in Asia and its commercial and historical center in Europe.[
Seven million foreign visitors arrived in Istanbul in 2010, when it was named a European Capital of Culture, making it the world's tenth-most popular tourist destination.[ The city's biggest draw remains its historic center, partially listed as a UNESCO World Heritage Site, but its cultural and entertainment hub has moved across the city's natural harbor, the Golden Horn, to the Beyoğlu district. Considered a global city,[ Istanbul hosts the headquarters of many Turkish companies and media outlets and accounts for more than a quarter of the country's gross domestic product. Hoping to capitalize on its revitalization and rapid expansion, Istanbul is currently bidding for the 2020 Summer Olympics.