The town's water supply, because of the lack of drinking water inside the Byzantine walls, which for centuries was provided by sources that are located 25 km North of Istanbul. Special danger of poisoning and destruction of water channels providing the city with water, existed during the war years and was very high. To solve this problem even in peacetime, the city begins construction of reservoirs.

The aqueduct was built under the Emperor Justinian, and brought water into the underground reservoir tank. The most famous and largest of them is the Yerebatan cistern or Yerebatan Sarancisi. It is also called the Basilica cistern, and it dates back to the VI century. The Yerebatan cistern is considered one of the largest, well-preserved to our time, the ancient reservoirs. This place is one of the most weird and wonderful in the world and represents a giant underground tank for water storage. Is this tank just opposite St. Sophia, almost in the historical centre of Istanbul.

The builders of the reservoir it was surrounded by a wall of refractory brick. Its thickness is 4 meters and covered it with a special waterproofing solution. Here was kept a reserve of drinking water in case of drought or siege of the city. The Turks who prefer flowing water stagnant, used on the destination stored in the water storage tank, and only watered her the gardens of Topkapi Palace.

To build this tank began in the reign of Constantine I 306-337 in and finished in the year 532, during the reign of Emperor Justinian. It was in the heyday of Eastern Rome, called the Byzantine Empire. The reservoir was actively used until the sixteenth century. It was subsequently abandoned and heavily polluted, and only in 1987 cleaned and renovated, the Yerebatan Cistern was opened to the public as a Museum.

Reservoir width 70 m. in length is 140 m. it Accommodates 80,000 cubic meters of water. A large number of columns placed at intervals of 4 m. In total, there are 336 – they represent a whole forest. Many of the columns once stood in the ancient temples and were brought to Constantinople from remote corners. Because of the difference in origin, columns differ markedly from each other, for example, the cultivar used to create marble, method of surface treatment, the amount of detail.

Function column bases perform two marble block with applied relief image of a monster of ancient legend – sleeveless Medusa, which, according to legend, could look to turn to stone any mortal. Column was located at the far end of the dungeon. Byzantine architects especially with them not stand on ceremony: one jellyfish fallen sideways and the other upside down. It is a deliberate humiliation of the ancient idol, not strange negligence. Near the jellyfish is a marble column with a relief pattern, which is called "peacock". This column is taken from the ruins of the Feodosia forum, now where is Beyazit square. The monuments of Constantinople, in turn, like the ruins of antiquity, turned into piles of construction material.

James bond in "From Russia with love" floated here on the boat, and film Director Andron Konchalovsky he shot scenes of his film "the Odyssey" (these are the moments when there are all sorts of horror when the light reflected in the water of the torches). The arches of this huge dungeon and the forest of columns with dripping water everywhere, however, and so makes a strong haunting with and without Konchalovsky for those who ever visited these places. In town is found about forty underground cistern, but it is possible that you will not find another.