Hagia Sophia is a former sixth century Christian church which was redeveloped into a mosque in the 15th century ; it ceased to be a place of worship when it became a museum in 1934. Its impressive esplanade is the perfect place to have a good view of these two iconic places Hagia Sophia and the Blue Mosque. There is a "postcard" picture to be taken at the fountain but avoid the touts at all cost because they will try and sell you a cruise on the Bosphorus three times the actual price (see cruise on the Bosphorus).
This ancient basilica/ part mosque was "offered to humanity" by Atatürk in 1934 when it became a museum. Its rich history is a unique testimony to Istanbul's religious tolerance.
To get a little more off the beaten track, take the little alley "Soguk Çeşme Sk" behind Hagia Sophia. This small street and charming homes will take you directly to the Topkapi Palace and its pleasant and relaxing park.
How to get there : By foot and tram stopping at Beyazit and discovering first the Grand Bazaar. Tram only: Sultanahmet stop (black line).
Meydanı Ayasofya, Sultanahmet Fatih, Turkey