The Valens Aqueduct | Bozdoğan Kemeri

The Valens Aqueduct (Turkish: Bozdoğan Kemeri, meaning "Aqueduct of the grey falcon"; Ancient Greek: Ἀγωγός του ὕδατος, Agōgós tou hýdatos, meaning simply "aqueduct") is a Roman aqueduct which was the major water-providing system of the Eastern Roman capital of Constantinople (modern Istanbul, Turkey). Completed by Roman Emperor Valens in the late 4th century AD, it was restored by several Ottoman Sultans, and is one of the most important landmarks of the city.
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The Long-Distance Aqueduct of Valens


Given the monumentality of the Aqueduct of Valens, it is sometimes hard to imagine that it was originally conceived as only a single component of a much grander scheme, which had probably been started in around AD 345. This was a vast and complex system, which supplied the city with water from a variety of sources in Thrace. At over 250km, it is the longest water supply line known from the ancient world and it remains one of the greatest achievements of hydraulic engineering. More than 30 stone water bridges and many kilometers of underground tunnels carried the water over mountain and plain from the plentiful springs of the Istranja mountains near Vize straight into the heart of the city.


Such was the magnificence of the undertaking that it even appears to have received its own popular mythology in the city it watered: an Ottoman writer was later to claim that the aqueduct had drained the great Danube river itself (Evliya Çelebi, Seyahatname, I, 484). The known system is at least two and half times the length of the longest recorded Roman aqueducts at Carthage and Cologne, but perhaps more significantly it represents one of the most outstanding surveying achievements of any pre-industrial society.


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