Istanbul is Turkey's most populous city as well as cultural and financial center. Located on both sides of the Bosphorus, the narrow strait between the Black Sea and the Marmara Sea, Istanbul bridges Asia and Europe both physically and culturally.
With its long history at the center of empires, Istanbul offers a wealth of historic and religious places to take in. The bulk of these ancient monuments, dating back to Roman, Byzantine, and Ottoman periods, including the Hagia Sophia, Topkapi Palace, Sultanahmet Mosque (Blue Mosque), and Basilica Cistern are located around Sultanahmet Square, while some others are dispersed throughout the peninsula of old city
North of the peninsula of old city, across the Golden Horn, is Galata, crowned by the Galata Tower. Istanbul Modern, with its exhibitions of contemporary Turkish art, is on the nearby waterfront of Karakoy. Another sight of religious significance close by is the Galata Whirling Dervish Hall of Sufi Mevlevi order, just north of the Tower. Further north is the Istiklal Avenue, Istanbul's prominent pedestrian street running from near Galata Tower to Taksim Square, the central square of whole city.
Heading west rather than north from the old city brings you deeper into the banks of the Golden Horn estuary. A neighbourhood perhaps well worth a visit here is Eyup, to visit city's holiest Islamic shrine and just to see what daily life in Ottoman Istanbul was like. On the opposite shores of the Horn, in Sutluce is the Miniaturk, the first miniature park in the city, with models from around the former Ottoman Empire.
North of Taksim Square is New Istanbul, main business district of the city. If venturing out to this direction, don't forget to check out Military Museum, where Ottoman military music concerts (Mehter) are held every afternoon. Most of the skyscrapers of the city are located in the north of this district, around Levent and Maslak, with a totally different skyline from that of the old city.
However southern reaches of the very same district has some fine neo-classical and Art Nouveau buildings from the turn of the 20th century, around the neighbourhoods of Osmanbey, Kurtulus, and Nisantasi. Just east from here, with a little drop in elevation as you approach the shore, is the banks of Bosphorus, that is lined by pleasant neighbourhoods full of waterfront mansions (yali) and a number of waterside palaces where you can admire what money could buy in times gone by.
Southeast of the city, off the southern coast of Asian Side are the Princes' Islands, an archipelago of nine car-free islands, characterized by stunning wooden mansions and pine groves.