The beauty of Istanbul is visible to the eyes, who could not spend several days enjoying all that this cosmopolitan city and full of history has with the most spectacular views of the Golden Horn? still Istanbul has hidden treasures from view and well worth discovering: hundreds of Byzantine cisterns that lie beneath its surface.

It is said that in the mid of s. XVI the Dutch researcher Petrus Gyllius was in Constantinople and stories came to him from the neighbors, assuring that in some houses there were water wells and even fish. This traveler managed to discover the entrance to the Basilica Cistern, which he relates in his travel notebooks.

THE ORIGIN

One of the main ways to bring water to Istanbul was through the Valente aqueduct, which transported it from the Belgrade forest, 19 km outside the walls, to the monumental fountain. A siege or an attack that destroyed the aqueduct left the city in a very vulnerable state. For this reason, during the Byzantine period the rulers made the decision to build a series of cisterns where they accumulate rainwater to have reserves.

It also served to transport water to the now-defunct Great Palace of Constantinople and other important buildings in the area, such as the Topkapi Palace. With the Ottoman conquest in 1453 the cisterns fell into disuse because they preferred running water to stored water.

DISCOVERING THE TANKS

Currently there are 60 cisterns that still remain, three of them have been opened to visitors: the Theodosius Cistern (Serefiye Sarnici), the Binbirdirek Cistern and the Basilica Cistern. Let's go down together to meet them.

Theodosius Cistern (Serefiye Sarnici)

The Cistern of Theodosius (Serefiye Sarnici) was built under ruler of Emperor Theodosius II (428 and 443 aD) to keep the water brought by the Aqueduct of Valente.

It is located in the Eminonu district. The cistern occupies an area of 1050 square meters. The ceiling reaches 9 meters in height and is supported by 32 marble columns, topped by Corinthian-style capitals.

The cistern came to light in 2010 when the old building of the Eminönü Municipality was demolished, where it was found underneath, without damaging its historical structure.

It took years to restore it until it was opened to the public in 2018. The entire structure is located under a huge glass and metal cube for its preservation. Currently its main use is as an exhibition hall.

Binbirdirek Cistern or Philoxenus Cistern

This Cistern, whose name means "Cistern of a Thousand Columns" is located west of the Hippodrome of Constantinople in the area of Sultanahmet

Its name means "Cistern of 1,001 columns", although it actually has 224.

According to sources it was built during the time of Constantine (Constantinus) in S. IV. Century, by order of the Roman senator Philoxenus, under the palace of Lausos.

It is the oldest cistern in the city, and the second largest (after Yerebatan) with an area of 3,610 square meters, with a capacity to store 40,000 cubic meters of water.

Its columns are 14 or 15 meters high and are made of marble from the island of Marmara. Each column is actually the superposition of two columns joined with a marble ring. The Greek letters on the bodies of the columns are the signs of the stonemasons who carved them.

After being completely destroyed in a fire in 475, it was rebuilt in the period of Justinian I in the 6th century until it fell completely into disuse and for the s. XVI was used as a workshop.

It is currently under concession for events, corporate dinners, parades and festivals, with a capacity of 1500 people.

Basilica Cistern

The best known and most beautiful of the cisterns is the Basilica Cistern or Yerebatan Sarnici. Its name means "Submerged Palace", which gives us a good idea of its grandeur.

Located near the Hagia Sophia (an old church and today a mosque), it was built in 532 during the reign of the Byzantine Emperor Justinian (527 - 565), although according to historians Constantine I had it built and was later rebuilt and expanded. It also supplied the Topkapi Palace after the Ottoman conquest for watering the gardens.

The cistern is six meters underground (52 stone steps must be descended), so in summer, the visit to the site is very pleasant due to the freshness of its atmosphere.

More than 7,000 slaves were used to complete this cistern, almost the size of a cathedral. Measuring 143 meters long by 65 meters wide, it is capable of holding 100,000 m3 of water. The dome is supported by 336 marble columns, each with a height of 9 meters. They have been scattered in twelve rows of 28 columns of Corinthian, Ionic and, to a lesser extent, Doric styles. Each one is believed to have been brought from other constructions.

Two restorations were carried out under the Ottoman Empire, one in 1723 under Ahmet III and the other in the 19th century under Sultan Abdülhamid II.

In 1968 damaged columns were repaired and in 1985 there was a restoration by the Istanbul Metropolitan Museum. The cistern was opened to the public on September 9, 1987.

The water was kept to a minimum level so that the public could appreciate the columns whose bases represent the head of the medusa. It is quite an adventure to go through the cistern until you discover them.

In Greek mythology, Medusa was one of the three gorgons, a monster with snakes for hair and who turned anyone who looked at her to stone. The origin of these two heads is totally unknown, but legend has it that in the Cistern they were placed face down in order to nullify the powers of her gaze. The most widely accepted theory is that they are from the late Roman period and were brought from another building.

At the end of the 20th century, walkways were painted that allow you to go through the entire cistern, before the visit had to be done by boat.

The Basilica Cistern has long been used in the film industry, as it is truly a movie set. In 007 From Russia with love (where you travel by boat) and more recently during the end of Inferno, the novel by Dan Brown starring Tom Hanks.