Built in 532 by Emperor Justinianus, the Yerebatan Cistern is also known as the Basilica Cistern because it is located under the Stoa Basilica. The cistern is 140 m long. Width 70 m.and it is a gigantic structure that covers a rectangular area. This cistern, which is laid with a staircase of 52 steps, has 336 columns in height of 9m. These columns rising in the water remind of a giant forest, and the visitors are fastinated as soon as they enter the cistern. The ceiling weight of the cistern is cruciform, the vaults are rounded, transferred to the pillars by arches, the bulk of the columns of granite cuts from various marble types, which are understood to have been gathered from older buildings, consist of one part and two parts on top of each other. The titles of these columns sometimes have different properties. While 98 of these reflect Corinthian style, rest of them reflects Dor style. The cistern is made of bricks, 4.80 m. Thick walls and brick-paved floors were plastered with a thick layer of Khorasan to make them water-impermeable. With a total area of 9.800 m2, this cistern has a water storage capacity of approximately 100.000 tons.
The cistern, in which 7,000 corpses worked, was built by emperor Valens. The length of the Valens (Bozdoğan) arch is 115.45 m. The water was brought with the help of Mağlova Belt in the length of 19 km.
The majority of the columns in the cistern, except for a few that are angular or grooved, are cylindrical. This column is known as the “Farum Tauri” in the Byzantine period. The time of the great Theodynius (379-395) is similar to the columns of victory. According to a hearsay, the shapes on them are similar to the tears of hundreds of slaves who died in the Great Basilica. 9 columns in the longest place and 2 columns in the narrowest place are not visible because 40 columns are behind these walls. Two Medusa heads used as pedestals under two columns on the northwest corner of the cistern are examples of masterpieces of Roman sculpture. It is believed that it is not an exact knowledge about which structure these were belonged to and brought here, but it was taken from an ancient structure belonging to the Roman Period and brought here.
Many rumors based on mythology about Medusa make it even more mysterious. According to a rumor, Medusa is one of the three Gorgons, the female monster of the underworld in Greek mythology. In this three sisters only Medusa is Snake Head. And he has the power to turn the person looks at her into stones. It is believed that Medusan was placed here with this thought, in order to protect the great buildings and private places from evil.
Again according to a personalized version, Medusa is a girl who boasted with black eyes, long hair and beautiful body. She loves The Greek God Perseus, the son of Zeus. Athene loves Perseus and envies Medusa. Athene makes Medusa’s hair look like terrifying snakes. To whom Medusa looks at, becomes stone. Perseus thinks that Medusa is enchanted, cuts her head, and takes the head to the wars. Those who see the head become stone and Perseus wins the wars.
After this, it is said that Medusa had been processed in the ancient Byzantine in reverse and sideways to the sword-snakes and column bases. According to another custom, Medusa saw herself in Perseus’s sword and turned into stone.
Yerebatan Cistern was used for a while after the conquest of Istanbul by the Ottomans in 1453 and the gardens of the Topkapi Palace were watered here. The cistern, which the Ottomans preferred to use tap water instead of stagnant water after they built their own water facilities in the city, was rediscovered by Dutch traveler P. Gyllius who came to Istanbul to investigate Byzantine remains in 1544-1550.
Basilica Cistern has been through various repairs since the day it was founded. The first restoration of the cisternwas in the 18th century. It was built by Mehmet Aga, architect from Kayseri. Second major repair was in the 19th century. It was in the time of Abdülhamit (1876-1909). The biggest reparation was initiated by Istanbul Municipality in 1985. It was completed on September 9, 1987, with 50.000 tons of mud being removed and the platform being built.
Yerebatan Cistern is open daily between 09.00 – 17.30 hours.