Strategically located on the Bosphorus peninsula between the Balkans and Anatolia, the Black Sea and the Mediterranean, Istanbul was successively the capital of the Eastern Roman Empire, and the Ottoman Empire and has been associated with major events in political history, religious history and art history for more than 2,000 years. The city is situated on a peninsula which is surrounded by the Golden Horn (Haliç), a natural harbor on the north, the Bosphorus on the east and the Marmara Sea on the south. The Historic Peninsula, on which the former Byzantium and Constantinople developed, was surrounded by ancient walls, built initially by Theodosius in the early fifth century.
The Outstanding Universal Value of Istanbul resides in its unique integration of architectural masterpieces that reflect the meeting of Europe and Asia over many centuries, and in its incomparable skyline formed by the creative genius of Byzantine and Ottoman architects.