Sultan Ahmet and the surrounding areas, as the center of Historical Peninsula, are the most vivid tourism center of Istanbul. It is the most important regions in Istanbul with Hagia Sophia Museum at one and Blue Mosque at the other, museums with rich collections, cisterns and hippodrome monuments.
Square in the south of Hagia Sophia was called Augusteion in the Byzantine period. There was the statue of Helena, mother of Constantine the Great, on a great column in middle of the square. It was the most important square of the city besides the Forum Constantine. In the southeast of the square there was Khalke Entrance, the entrance of the Grand Palace and around the square baths and palaces of important peoples were aligned.