The Basilica Cistern in Sultanahmet was built in 542 by the Byzantine Emperor Justinian to meet the water needs of the then Great Byzantine Palace on the other side of the Hippodrome.
The Turks did not realize that the cistern had existed for about a century after their conquest until it was discovered that people were catching fish in the water accumulated under their basements by hanging baskets from holes. The houses blocking the entrance of the cistern, which was repaired and used during the Ottoman period, were expropriated by the Istanbul municipality in the 1940s and a more appropriate entrance gate was built.
Between 1985 and 1988, the Istanbul Metropolitan Municipality undertook a major restoration effort in the cistern and purged the sludge accumulated in the bottom; a jetty was built all the way to its western most point, and a platform was added in the northeast corner.
The cistern is called the Yerebatan (Sunken) Palace and is 145 meters long and 65 meters wide. It covers an area of approximately 9,800 square meters. It holds 12 rows of brick arch columns, with 28 columns in each row supporting the vaults. Of the 336 columns in total, eight of the columns have been enclosed in a protective sheath in the northern section, and 37 columns in the southwest have been enclosed by an infilled wall.
While the cistern was dry during the last restoration, water has been gradually refilling the cistern, and today there is one to two meters of water. Istanbul Kültür ve Sanat Ürünleri Ticaret A.Ş. runs the Basilica Cistern, where Istanbul Metropolitan Municipality organizes various cultural activities.
One of the magnificent historical structures of Istanbul is the Basilica Cistern, located across the street to the southwest of Hagia Sophia. This large underground cistern, built by the Byzantine Emperor Justinian I (527-565), has been named appropriately as the “Sunken Palace” by the public based on the marble columns which look as if they go on forever.
