Although the exact date of its construction has been lost in history, the Valens Aqueduct, also known as the Hadrianus Aqueduct, is a legacy of the Late Roman and Early Byzantine era. Over the centuries, the structure fell into disrepair and eventually to ruins, until the conquest of the city, when it was restored in order to deploy its original function: namely, to distribute water in periods of regional shortage.
It is believed that when first constructed; the aqueduct was more than 1 kilometers in length. Over the years, additions have been made, although the point at which the structure was given its Turkish name “Bozdoğan” is unknown. Today, the preponderance of the once sprawling aqueduct has largely been destroyed, with the notable exception of the remains found on the Saraçhane Atatürk Boulevard.
In 1988, the Municipality of Istanbul decided to restore this piece of history which also bears witness to Ottoman design. Being the oldest aqueduct in İstanbul, Valens has served the city for more than 15 centuries as its most important water source.