Istanbul is one of the world’s great cities. Superbly situated either side of the blue ribbon of the Bosphorus Strait separating Europe from Asia it is, unlike any other city in the world, split between two continents. The old quarter, with its oriental-fantasy skyline of domes and minarets, and its narrow cobbled streets lined with quaint old wooden houses, lies on a tapering peninsula pointing gravely across the straits to Asia. To the south, the blue waters of the Sea of Marmara glitter invitingly. North, across the graceful curve of the Golden Horn, flicker the bright lights of the pulsating entertainment quarter of Beyoğlu.
Istanbul is a booming mega city, with a population exceeding 15 million, a vibrant stock exchange and a skyline which, in the business districts beyond Beyoğlu, is beginning to resemble Manhattan. More importantly, it is an ancient city, originally founded by the Greeks in the seventh century BC. In the fourth century AD it became Constantinople, capital of a Byzantine Christian world which kept the warriors of Islam from Western Europe for several centuries, before finally falling to the Ottoman Turks in 1453. The relics of these two great powers stud the old quarter, from the mighty Byzantine Church of the Holy Wisdom (Aya Sofya), through to the splendid pavilions of the fulcrum of the Ottoman Empire, the Topkapı Palace.
September and October’s generally clear, sunny days provide the ideal weather to explore in the best possible way - on foot - but it is still plenty warm enough to eat outside, take a Bosphorus Cruise or even swim in the Sea of Marmara from one of the pretty Princes’ Islands.
by Terry Richardson (from http://www.telegraph.co.uk/travel/)