Measurements and data This cathedral-sized cistern is an underground chamber of 143 by 65 metres, capable of holding 80,000 cubic metres of water. The large space is broken up by a forest of 336 marble columns each 9 metres high. The columns are arranged in 12 rows each consisting of 28 columns. The capitals of the columns are mainly Ionic and Corinthian styles, with the exception of a few Doric style with no engravings. According to ancient historians, emperor Constantine had already built a basilica and cistern on the same spot. As the demand for water grew, emperor Justinian enlarged the cisterns and incorporated the basilica. The cistern is surrounded by a firebrick wall with a thickness of 4 meters and coated with a special mortar for waterproofing. The cistern's water was provided from the Belgrade Woods—which lie 19km north of the city—via aqueducts built by the emperor Justinian. The cracks and the columns were repaired in 1968. Having been restored in 1985 by the Istanbul Metropolitan Museum, the cistern was once again opened to the public on September 9, 1987. Medusa column bases The bases of two of the columns reuse earlier blocks carved with the head of a Medusa. They are located in the northwest corner of the cistern. It is not known exactly where the origin of the two heads is. It is rumoured that the heads were brought to the cistern after being removed from an antique building of the late Roman period. Another mystery is about why one of the heads is upside down, while the other one is tilted to one side. But it is commonly accepted by scientists that they were placed that way deliberately. Trivia The cistern was used as a location for the James Bond film From Russia with Love. It is a popular tourist attraction.