Istanbul is an intriguing city that thrives at the interface: between east and west, Islam and Christianity, antiquity and modernity. It is a city of monuments spanning two millennia, including the Hagia Sophia which was constructed and reconstructed while Istanbul was the capital of the Byzantium Empire, and the Topkapi Palace and Blue Mosque which were constructed later during the Ottoman Empire.
One of the city’s most unusual attractions, however, is situated deep underground: a cavernous enclosure known as the Basilica Cistern. Constructed in the sixth Century by emperor Justinian I, it was designed as one of several important stores of water to nourish the half-million inhabitants of the city, and supply the city’s countless public baths, gardens and fountains. Supported by 336 columns of Ionic and Corinthian style sourced from various corners of the empire, it has a total area of 9800 m2 and a storage volume of 80,000 m3.
The cistern is just one element of a much more complex water distribution network. It was designed to draw water from ancient springs scattered throughout Thrace, and convey it to the city via a complex network spanning more than 250 km and comprising more than 30 aqueducts, kilometers of underground tunnels and above-ground canals, approximately 70 cisterns and (possibly) some dams further upstream. It is described as one of the ancient world’s greatest achievements of hydraulic engineering, surpassing the infrastructure of ancient Rome in both scale and complexity. Importantly, it not only provided an essential resource during peacetime, but also had a military purpose to protect the city during sieges, with parts of the network running parallel to the city’s defense walls and with the total constructed storage capacity within the walls adding up to close to a million cubic metres.
With its scale and importance, it is staggering that at some point in its history the cistern was lost, only to be re-discovered in the mid-sixteenth century by the French scholar Pierre Gilles who observed that the inhabitants were drawing water from wells underground, not knowing from whence the water came. It was then recommissioned and used by the Ottoman Empire to supply water to the Topkapi palace, and is now used as a museum as well as a venue for occasional concerts due to its remarkable acoustics.
When walking around the cistern today it is hard not to feel awed by its grandeur, and the no-doubt considerable cost of its construction. On one of the columns, carvings of teardrops can be seen covering its eight metre height, which are said to represent the hundreds of slaves who died during the cistern’s construction. We also came across two statues of Medusa, one placed upside down and the other on its side, so that those looking at her would not be turned to stone. The purpose of these statues is unknown, but one of the rumours is that she was placed there to protect large structures in special locations. The fact that the cistern is still intact one and a half millennia after its construction suggests that she has been extremely successful in executing her role.