The Basilica Cistern (Turkish: Yerebatan Sarayı – “Sunken Palace”) is the largest of several hundred ancient cisterns that lie beneath the city of Istanbul (formerly Constantinople). The cistern, located 500 feet (150 m) southwest of the Hagia Sophia on the historical peninsula of Sarayburnu, was built in the 6th century during the reign of Byzantine Emperor Justinian I.
The name of this subterranean structure derives from a large public square on the First Hill of Constantinople, the Stoa Basilica, beneath which it was originally constructed. Before being converted to a cistern, a great Basilica stood in its place, built between the 3rd and 4th centuries during the Early Roman Age as a commercial, legal and artistic centre. The basilica was reconstructed by Illus after a fire in 476. Historical texts claim that 7,000 slaves were involved in the construction of the cistern. The enlarged cistern provided a water filtration system for the Great Palace of Constantinople and other buildings on the First Hill, and continued to provide water to the Topkapi Palace after the Ottomanconquest in 1453 and into modern times.
This cathedral-size cistern is an underground chamber approximately 138 metres (453 ft) by 64.6 metres (212 ft) – about 9,800 square metres (105,000 sq ft) in area – capable of holding 80,000 cubic metres (2,800,000 cu ft) of water. The ceiling is supported by a forest of 336 marble columns, each 9 metres (30 ft) high, arranged in 12 rows of 28 columns each spaced 4.9 metres (16 ft) apart. The capitals of the columns are mainly Ionic and Corinthian styles, with the exception of a few Doric style with no engravings. One of the columns is engraved with raised pictures of a Hen’s Eye, slanted braches, and tears. This column resembles the columns of the Triumphal Arch of Theodosius I from the 4th century (AD 379–395), erected in the ‘Forum Tauri’ Square. Ancient texts suggest that the tears on the column pay tribute to the hundreds of slaves who died during the construction of the Basilica Cistern. The majority of the columns in the cistern appear to have been recycled from the ruins of older buildings, likely brought to Constantinople from various parts of the empire, together with those that were used in the construction of Hagia Sophia. They are carved and engraved out of various types of marble and granite.
The Basilica Cistern has undergone several restorations since its foundation. The first of the repairs were carried out twice during the Ottoman State in the 18th century during the reign of Ahmed III in 1723 by the architect Muhammad Agha of Kayseri. The second major repair was completed during the 19th century during the reign of Sultan Abdulhamid II (1876–1909). Cracks to masonry and damaged columns were repaired in 1968, with additional restoration in 1985 by the Istanbul Metropolitan Museum. During the 1985 restoration, 50,000 tons of mud were removed from the cisterns, and platforms built throughout to replace the boats once used to tour the cistern. The cistern was opened to the public in its current condition on 9 September 1987. In May 1994, the cistern underwent additional cleaning.
