1400 year old underground water tank in Istanbul

1400 year old underground water tank in Istanbul

In the historical city of Istanbul, Turkey, there are many monumental buildings from the Byzantine era, the most famous of which is the Hagia Sophia, which was a church before the conquest of Constantinople. In Istanbul, the Romans also built several underground cisterns to store water, including 9800. Covering square meters, the "Basilica Cistern" is the largest which was built in the 6th century AD during the reign of the Byzantine emperor Justinian I (Justinian I).

This earthen cistern is built inside a large basilica located 150 meters southwest of the Aya Sofia mosque. During the Roman period, such houses were built for public gatherings where sports competitions, public courts and art exhibitions were held, while large cisterns were built in their basements where rainwater was stored. According to historians, a huge palace was built at this place during the 3rd and 4th centuries AD, which was destroyed by fire and rebuilt in 476 AD. Later, during the reign of Emperor Constantine, the structure of the present building was constructed, and then during the reign of Emperor Justinian I, an underground water tank was also constructed here while expanding further. According to ancient traditions, 7 thousand slaves participated in the construction of Basilica Cistern.The walls of the vast Basilica Cistern are made of paved bricks, which are 13 feet thick, while the walls are coated with a special spice layer to prevent water ingress. There are 52 stone steps to descend into the reservoir. The roof of the tank is supported by 336 pillars of marble and granite stones. Each pillar is 30 feet high and is erected in 12 rows and 28 columns. Each pillar is 16 feet apart from other pillars. A number of small arches are made in the roof of the tank so that the weight of the roof can be transferred to the pillars in an efficient way. Interestingly, all the pillars for this tank were not built anew, but most of them were removed from abandoned buildings in different parts of the empire and moved here.

The water storage capacity of this underground reservoir is 2.8 million cubic feet. To fill the reservoir, water was brought here from the Belgrade forest, 19 miles north of Istanbul, through underground canals. These underground canals were also used by Emperor Justinian I. It was built during The stored water was supplied to the imperial palaces of Constantinople after the purification process. In 1453 AD, when the Ottomans conquered Constantinople, water from here was brought to the royal palace of the Ottomans.The 1400-year-old Basilica Cistern has undergone many renovations. Its first repair was done in 1723 during the reign of Ottoman Sultan Ahmed III, while the second major repair took place in the nineteenth century during the reign of Sultan Abdulhamid II. Later, in 1968 and 1984, large-scale repair work was done here and 50,000 tons of silt was removed from the bottom of the reservoir.The minimum water level in the bottom of the cistern is always maintained for the interest of the tourists visiting the Basilica Cistern.