Valens aqueduct

Valens Aquaduct, Istanbul 1 by Rolyatam

The Valens Aqueduct (Turkish: Bozdoğan Kemeri) is an aqueduct in the European part of Istanbul, Turkey, constructed by the Romans during the 4th century.

The aqueduct usually called that of Valens (328 – 378) was actually completed in 368 during the reign of this Eastern Roman emperor, but certainly planned and begun already in the time of Constantine the Great (272 - 337) or his son Constantius II (317 – 361). The aqueduct was built as part of a new water supply system for Constantinople. Water from the Belgrad Forest beyond the city was carried over the aqueduct to the center of the city around the Great Palace near the Hippodrome. It was in use throughout the Byzantine and most of the Ottoman periods.

The aqueduct with double-tiered arches, which stretched across the little valley between two of the city's seven hills (Fatih and Süleymaniye), was originally over 1,000 m long and 26.5 m high in the middle. The impressive structure, still intact, has today a length of 971 m and a maximum height of only 20 m, since the surrounding ground level has risen up to 6 m. It was used during the Ottoman period for one branch of the Halkalı water supply system and repaired during the reign of Suleiman the Magnificent (1520-1566) and later of Mustafa II (1695 - 1703).

The Istanbul Municipality extensively repaired the Bozdoğan Kemeri in recent years by replacing cracked stones, and exposed the parts that were formerly below ground level to reveal the original brickwork technique. Today, it spans over a major avenue that runs through the old part of city connecting Atatürk Bridge on the Golden Horn with the Aksaray quarter in the borough of Fatih. Since early 2007, the aqueduct is illuminated at night with an LED lighting system of changing colours.