Spanning Europe and Asia, exotic Istanbul is one of the world's most fascinating cities. Domes and minarets enhance the skyline. In the old Stamboul area, traces remain of every city built since the community was established over 600 years before Christ. Once Rome's eastern capital, Istanbul was also the center of the huge Ottoman Empire. Landmarks include Hagia Sophia, once Christendom's greatest church; the Blue Mosque with its striking Iznik tiles; Topkapi Palace, containing a sultan's ransom of treasures; Chora Church with its Byzantine mosaics; and the Grand Bazaar, the ultimate shopping experience. Explore Condé Nast Insider Tips for Istanbul