The entrance to the Basilica Cistern is located just across the street from Hagia Sophia. It is an underground reservoir built in 502 during the reign of Justinian I, to ensure the water supply to the Great Palace. The cistern is capable of holding approximately 80,000 cubic meters of water and was fed by the Valens Aqueduct with water from the Belgrade Forest. The aqueduct is reported as being 971 meters long.
The cistern was all but forgotten until it was rediscovered in 1545 by Peter Gyllius, a Frenchman who was in the city, then called Constantinople, searching for antiquities from the Byzantine period. Gyllius noticed that some locals got their water by simply lowering buckets through holes in their floors, on some occasions, they even brought up fish with the water. He searched for, and eventually found the entrance.
The Basilica Cistern was restored and cleaned, and then in 1987 opened to the public. Access is gained by descending a flight of steps down into the cistern. Walkways were created in the 1990’s enable the visitor a comprehensive view of this engineering masterpiece. Atmospheric lighting and soft music was also introduced adding to the overall effect.
The roof of the Basilica Cistern is supported using 336 marble columns most of which are in either the Iconic or Corinthian style. Each column is 9 meters high, and spaced at four meter intervals, they are laid out in 12 rows with each row containing 28 columns.
If you walk to the far left-