Basilica Cistern is the largest of several hundred ancient cisterns that lie beneath the city of Istanbul. It had provided water for the Great Palace of Constantinople and other buildings on the first Hill. Also It had continued to provide water to the Topkapi Palace after the Ottoman Conquest in 1453.
It has been a museum since 1967. The two heads of Medusa as bases of two columns stand in the northwest corner of the cistern. But, there is not enough writing about origin of two heads. Though, Byzantines had recycled them while building the cistern during 6th century.
The Byzantines had called this underground cistern, Basilica. Because it was under a large public square. There was a great basilica in its place from 3rd century. It was the legal and commercial center. Byzantines had reconstructed it after a fire in 476. According to ancient text, this oldest basilica had gardens with columns. After the riot of Nike, Emperor Justinian had built Basilica cistern with Hagia Sophia at the ground of Basilica Church.
According to historians, around 7000 slaves had worked to build construction of cistern.
Byzantine cisterns (water reservoirs) were very famous architecture in history. . Constantinople had always drinking water problems. Therefore they had cisterns to every corner of royal city to reserve the spring water. Also these underground ones were hidden because of providing water to royal buildings.
Actually this Basilica cistern is quite popular in media with famous movies. They had filmed 1963 James Bond Film “From Russia with Love”. Also latest, They had used the building to film “Inferno” in 2009.
Management belongs to Municipality of Metropolitan Istanbul. It is a museum opened everyday. But Nowadays it is under renovation. Yerebatan Sarnıcı, Underground Cistern, Underground Palace, Basilica Cistern are the names of ancient building.