The construction which was built by Emperor Justinian I in the 6th Century AD is located in Sultanahmet. Yerebatan which has been called Basilica Cistern due to its close location to Hagia Sophia for centuries has been built by caving the rocky ground 25 meters under the surface. The many columns in the cystern which is 138 meters long and 64 meters wide made the building be called yerebatan (sunken) palace by the public. The cistern which was built to find a solution to the water shortage experienced in the city is the biggest cistern ever found in Constantinopolis. It is known that the water provided from Belgrad forests is brought to the cistern via the Cebeciköy aqueduct. There are total 336 columns in the cistern which has a water capacity of total 80.000 cubic meters. On some of these columns there are ornamental elements and two of them are adorned with Medusa Heads.
It is known that during the Ottoman Empire the water inside the cistern was only used for watering the gardens. The restoration of the cistern took place between 1985-1988. In the cistern which became a magical place with catwalks between the columns and light effects, rain water is collected and several art events such as the 8. Bienal of Istanbul which was organised in the year 2003 are organized. The Cistern is open to visit every day except Tuesdays