Historically known as Constantinople and Byzantium, Istanbul is the economic, cultural, and historic center of Turkey. The much fought-over city fell to the Ottomans in the 15th century, morphing into Istanbul over time. The city straddles the Bosphorus Strait at the convergence of Europe and Asia Minor—or, where east meets west both geographically and culturally.Today, the city is largely Turkish but has a largely cosmopolitan feel due to its 14 million inhabitants. Along with its historic monuments and palaces, Istanbul has a flourishing arts and music scene peppered with trendy bars, clubs, art galleries, and designer fashion outlets.UNESCO has declared much of the old city area UNESCO World Heritage sites, including the Hagia Sophia cathedral, Sarayburnu, and Topkapi Palace.Travelers can cross from Europe to Asia at the Bosphorus Strait with no passport required. Here they'll find the district of Kadiköy, which features bustling street markets, good shopping, and an up-and-coming dining scene.