Yerebatan Sarnıcı

The Basilica Cistern is one of the structures that have survived from the Byzantine era to the present day. Located southwest of Hagia Sophia in the place area, this building was constructed by Emperor Justinian I (527–565) to meet the city’s water needs. Due to the columns rising from the water, it has been called the “Underground Palace” among people.

Architectural Structure and Features

The cistern is a rectangular structure measuring 140 metres in length and 70 metres in width. It contains 336 columns, each 9 metres high. These columns are arranged in 12 rows, with 28 columns in each row. The weight of the ceiling is distributed through arches between the columns. Many of the columns were reused from earlier structures; some are made of a single piece while others consist of two parts.

The walls of the cistern are constructed of brick 4.80 metres thick and rendered with Horasan mortar to make them watertight. Covering a total area of 9,800 m², the structure has a water capacity of approximately 100,000 tons.

Yerebatan Sarnıcı-Wikipedia

Medusa Heads and Mythological Legends

Two Medusa heads are located in the northwest corner of the cistern. It is not definitively known from which structures these heads were taken, though they are recognized as examples of Roman-era statue art. Some researchers believe they were placed here specifically to serve as column bases.

However, numerous mythological legends surround Medusa. According to Greek mythology, Medusa was one of the three Gorgon sisters and possessed the power to turn anyone who looked at her into stone. Another legend states that Medusa, whose hair was turned into snakes by Athena, was slain by Perseus, and her severed head was used as a weapon in battle. It is known that during the Byzantine period, such symbols were employed to ward off evil spirits. For this reason, it is believed that the Medusa heads were placed in the cistern for protective purposes.

The Basilica Cistern Through History

During the Byzantine era, the cistern supplied water to the city and continued to be used as a duration after Istanbul was conquered by the Ottomans. However, since the Ottomans preferred flowing water over stagnant water, they gradually constructed their own water systems and reduced the cistern’s use.

Until the mid-16th century, the Basilica Cistern remained unknown to the Western world. It was discovered in 1544–1550 by the Dutch traveler P. Gyllius, who introduced it to Western scholars. Gyllius learned that residents of houses near Hagia Sophia were drawing water and fishing from wells in their ground floors, leading him to deduce the existence of a large underground structure. Entering the cistern with a torch, the traveler made measurements, identified the columns, and published his findings in his travelogue.

During the Ottoman period, the cistern underwent two major restorations: under Sultan Ahmed III (1723) and Sultan Abdulhamid II (1876–1909). In the Republican era, it was cleaned by the Istanbul Municipality in 1987, a viewing platform was added, and it was opened to the public. It underwent another restoration in 1994.

The Basilica Cistern Today

The Basilica Cistern continues to exist not only as a museum but also as a cultural site hosting numerous national and international events. USA former President Bill Clinton, Netherlands Prime Minister Wim Kok, and former Italian Minister of Foreign Affairs Lamberto Dini, among many other famous figures, have visited the cistern.