With its strategic location on the Bosphorus peninsula between the Balkans and Anatolia, the Black Sea and the Mediterranean, Istanbul has been associated with major political, religious and artistic events for more than 2000 years. Its masterpieces include the ancient Hippodrome of Constantine, the 6th century Hagia Sophia and the 16th century Suleymaniye Mosque, all now under threat from population pressure, industrial pollution and uncontrolled urbanization.
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.