Mrs Oz guided us in a small group in about 7 hrs time to all main attractions in Istanbul: Topkapi Palace, Blue Mosk, Hagia Sofia, Grand Bazar. She also took us to the Basilica Cisterns (not included in price). This is the best way to see the most important historical sites in old Istanbul if you have only limited time. Its a skip-the-line all in one package including a fine Turkisch lunch. English is good. Booked through whatsapp: quick and clear. Total price 270 TL/90 USD pp.