Istanbul, Turkey, is balanced between Europe and Asia both physically and culturally. Located on both sides of the Bosphorus, the narrow strait between the Black Sea and the Marmara Sea, Istanbul is Turkey’s cultural heart and with a population of somewhere between 12 and 19 million people, one of the largest cities the world. With a history dating back to the Roman, Byzantine, and Ottoman empires, it offers a wealth of historic and religious sites to visit. Of particular interest to tourists is Sultanahmet Square, where you’ll find Hagia Sophia, Topkapi Palace, the Blue Mosque and Basilica Cistern. Start an Istanbul experience and take advantage of United Airlines® superb flight options.