Cistern of the Hebdomon

The cistern is located in Istanbul, in the district of Bakırköy, in the mahalle of Osmaniye, between Fildamı Arkası and Çoban çeşme Sokak, to the northwest of the Veli Efendi horse race track. Topographically, it lies about 2 km west of the Golden Gate of the Walls of Constantinople, in the western part of a small valley – now completely built up – which runs southwards to the Marmara sea. ==History==

The date of construction of this cistern, which lay in the outskirts of the Hebdomon (, "the Seventh", so called because of its location seven Roman miles from the Milion, the mile-marker monument of Constantinople), is uncertain, but can be placed from the fifth-sixth centuries to the eighth century. lay in the valley of Veli Efendi, where now Istanbul's horse race track is placed. After the Fall of Constantinople in 1453, the empty reservoir was used by the Ottomans as a stable for the Sultan's elephants, whence its Turkish names Filhane or Fildamı, meaning house or repair of the elephants. Afterwards, it was used as vegetable garden, becoming one of Istanbul's four Çukurbostan ("hollow garden") still extant, By 2003, it had become clear that the vibrations of the music were damaging the walls and disturbing the horses in the nearby race track, and the concerts ceased. Since then, the structure – administered by the belediye of Bakırköy – has been sporadically used to host meetings. ==Description==

The cistern has a rectangular plan with sides long and wide, and covers an area of about . The same pattern was also used to build the cisterns of Aetius, of Aspar and of Mocius inside the walled city of Costantinople. The outer western wall is buried in the hill, while the inner western wall and the outer eastern wall are reinforced with a series of nineteen semicircular projecting niches which create two buttresses, necessary to withstand the weight of the hill. The tower has a double shell structure, with a spiral staircase in the centre, separated from the outside by a casing containing the water flowing from an inflow placed at the bottom of the tower. The central one is destroyed, while the other two, still extant, are named Domuzdamı ("house of the pigs"), since they were used as stables for animals. ==See also==