TheCistern ofMocius (Greek:κινστέρνη τοῦ Μωκίου), known inTurkish asAltımermer Çukurbostanı ("sunken garden of Altımermer"),[1] was the largestByzantine open-sky water reservoir built in the city ofConstantinople.[2]
The cistern is located inIstanbul, in the district ofFatih (thewalled city), in the quarter ofAltımermer and themahalle ofSeyyid Ömer, to the northeast of the Seyyid Ömer Mosque, betweenZiya Gökalp Sokak to the north andCevdet Paşa Caddesi to the south. It lies on the highest part of theseventh hill of Istanbul, and overlooks theMarmara Sea.
According to thePatria of Constantinople, the construction of this cistern, which lay in the twelfth region of Constantinople, occurred underEmperorAnastasius I (r. 491–518).[2] The name came from the important church dedicated toSaint Mocius, which was located near the southwest corner of the reservoir.[3] The cistern, which lay just outside theWall of Constantine, which formed the city's original landward boundary, was built to supply water to the new quarters erected between the former and the 5th-centuryTheodosian Walls.[4] Writing after theOttoman conquest of 1453, the 16th-century French travelerPierre Gilles observed that around 1540 the reservoir was empty.[2] In theOttoman period, as itsTurkish nameÇukurbostan ("hollow garden") betrays, the structure was used as vegetable garden, usage which remained until the end of the 20th century. As of 2014 the area is used as "Educational Park" (Turkish:Fındıkzade Eğitim parkı) of theFatih district.[5][6]
The cistern has a rectangular plan with sides 170 metres (560 ft) long and 147 metres (482 ft) wide, and covers an area of 25,000 square metres (270,000 sq ft): this makes of it the largest cistern ever built in Constantinople.[2] Its average depth is unknown, since the reservoir is partly filled with earth, but it should range from 10.50 metres (34.4 ft) to about 15 metres (49 ft), of which 2–4 metres (6.6–13.1 ft) are still visible.[2][3][7] The reservoir could contain about 0.260–0.370 million cubic metres (69–98 million US gallons) of water. Its walls, 6.00 metres (19.69 ft) thick[1] and partially still in place,[3] were built using theRoman construction techniqueopus listatum, by alternating courses of bricks and of stone,[5] an elegant pattern similar to that also used by the similar cisternsof Aetius andof Aspar.
41°0′37″N28°56′05″E / 41.01028°N 28.93472°E /41.01028; 28.93472