Built in 375 AD, The Aqueduct of Valens, locally known as the Bozdoğan Kemeri, is one of Istanbul’s remarkable historical landmarks.
Introduction
Its story is one of architectural genius, resilience, and the sustained significance of water management across empires.
This kilometer-long aqueduct of which about 800 meters still survive was almost certainly built on the site of an older version. It was created out of stones taken from the walls of Chalcedon that had been demolished after the locals rose up in support of Procopius, the cousin of the Emperor Julian, against the Emperor Valens in 365. For much of its length it features a double tier of arches 18.5 meters high.
- Saffet Emre Tonguç (Istanbul – The Ultimate Guide (77th Edition – p. 109)
From its construction in the Byzantine era to its revival under Ottoman rule, the aqueduct symbolizes the resourcefulness and ingenuity of the city’s early planners and leaders. In this post, we delve into the history, importance, and structural features of the Aqueduct of Valens, examining how it once served as a vital artery, supplying the lifeblood of a great city.
Table of Contents
A Byzantine Solution to a Growing Need
Constructed under the reign of Emperor Valens in the 4th century AD, the aqueduct was designed to address a critical need: fresh water for the ever-expanding population of Constantinople. As the capital of the Eastern Roman Empire, Constantinople was not only growing in population but also in its strategic and economic importance.
Emperor Valens commissioned this ambitious project to create a reliable water supply that could support the demands of an imperial capital. The aqueduct became a crucial link in an extensive water network, channeling water from natural springs as far as 250 kilometers away into the heart of the Byzantine city. This impressive infrastructure secured Constantinople‘s water supply, safeguarding its population and reinforcing its position as a leading metropolis of the ancient world.
Location and Architectural Marvels
Stretching across the heart of Istanbul, the Aqueduct of Valens spans nearly 970 meters, connecting the hills of the historic peninsula. Although the original structure was much longer, the surviving section today passes over Atatürk Boulevard, a busy thoroughfare in Istanbul’s Fatih district. Rising to heights of up to 29 meters, its striking arches dominate the skyline, blending into the urban landscape while standing as a testament to ancient engineering.
The aqueduct’s construction showcases the ingenuity of Byzantine architecture, with two tiers of arches constructed from local limestone and granite, providing both strength and durability. These materials and the aqueduct’s design not only ensured resilience against time and natural disasters but also allowed the structure to carry significant volumes of water efficiently. The clever distribution of arches and weight-bearing pillars reflects an advanced understanding of both engineering and aesthetics, as the structure appears as grand and balanced today as it did centuries ago.
The Aqueduct in Byzantine Constantinople
Under Byzantine rule, the Aqueduct of Valens was more than just infrastructure; it was a representation of the empire’s wealth, power, and commitment to urban welfare. Stretching across Constantinople’s third and fourth hills—two of the city’s iconic seven hills, which paralleled the layout of Rome—this aqueduct played a strategic role in connecting different parts of the city.
Maintaining this vital structure became an imperial priority, as it ensured access to water for public baths, palaces, fountains, and the city’s everyday needs. During sieges and times of crisis, the aqueduct network allowed the city to remain self-sustaining, a key factor in Constantinople’s endurance through centuries of conflict.
The Byzantine emperors maintained and expanded this water system, connecting the aqueduct to a network of cisterns and reservoirs across the city. Some of these cisterns, like the famous Basilica Cistern, still survive today, offering a glimpse into the complex and layered approach to water management practiced by the Byzantines.
Revival and Enhancement in the Ottoman Period
After the Ottoman conquest of Constantinople in 1453, Sultan Mehmed II quickly recognized the importance of the Valens Aqueduct in supplying water to his new capital. The Ottomans repaired and expanded the aqueduct, integrating it into their own hydraulic network and ensuring it could meet the needs of Istanbul’s growing population. The aqueduct was essential in channeling water to mosques, palaces, and public spaces, including the Topkapi Palace and the sprawling Suleymaniye Mosque complex. This effort reflected the Ottomans‘ appreciation for the infrastructure of previous empires and their understanding of the significance of effective water management.
Under successive sultans, the aqueduct continued to receive regular maintenance and was adapted to Istanbul’s changing landscape and demands. This ongoing stewardship allowed the aqueduct to remain functional and relevant, highlighting the Ottomans’ respect for Byzantine engineering and their commitment to preserving the practical and aesthetic qualities of the city.
Structural Brilliance and Enduring Legacy
The Aqueduct of Valens stands as a structural masterpiece, embodying both functionality and elegance. Its arches—designed in double tiers—allowed the aqueduct to traverse hills and valleys, adapting seamlessly to the natural terrain. This tiered design was essential for maintaining water pressure and ensuring a steady flow. By using resilient materials and sophisticated design principles, the aqueduct could withstand the earthquakes that frequently affected the region, standing tall through centuries of wear and tear.
The aqueduct’s role in Istanbul’s water supply persisted for centuries, bridging the Byzantine and Ottoman eras with its enduring functionality and beauty. It stands today as a symbol of Constantinople’s legacy as a city of grand designs and sophisticated urban planning, inviting both locals and visitors to marvel at its enduring strength and elegance.
Conclusion
Today, the Aqueduct of Valens is a prominent feature of Istanbul’s historic Fatih district, although it is not yet allowed to get on top of it. The current mayor Ekrem Imamoglu wants to make it accessible for the public to visit it. However, that requires some time.
This incredible ancient structure serves as a powerful reminder of the Roman Empire’s early presence in Istanbul -even before the Byzantines, representing an era when water infrastructure was as crucial as city walls in sustaining an empire. For those walking along Atatürk Boulevard or exploring the nearby parks, the aqueduct offers a window into a world where architectural prowess was aligned with the needs of a thriving metropolis.
As Istanbul continues to grow, the Aqueduct of Valens remains an emblem of resilience and ingenuity, bridging Istanbul’s ancient past with its vibrant present. Visiting the aqueduct is not only a journey back in time but also a testament to the role that advanced engineering and thoughtful urban planning have played in Istanbul’s storied past.
Contact Us for a Guided Tour
Even though it’s not strictly legal to walk on the Valens Aqueduct, we still offer tours around it where you can touch this very special structure and learn all about its history.
We can also show you around the nearby neighborhood Zeyrek, as well as take a bath in the newly restored 16th century Zeyrek Çinili Hamam which received its waters from this aqueduct for centuries. And this bath is arguably the very best Turkish bath in the whole wide world!! It was built by Sinan the Great afterall…
The Aqueduct of Valens is indeed an impressive structure, and it’s fascinating to see how such engineering marvels from the Roman Empire have been integrated into modern Istanbul. Of course, the credit for its construction goes to the genius of Roman architects, who laid the foundation for what became Constantinople—the city at the heart of our shared Byzantine heritage. While I admit it’s well-preserved under Turkish care, it’s hard not to feel a twinge of regret knowing these masterpieces now stand as symbols of a history that has, let’s say, shifted hands dramatically. Still, it’s good to see our ancestors’ legacy being appreciated, even if the context has changed over the centuries. Let’s hope it remains as well-tended in the future!
Thank you for your comment and for recognizing the magnificence of the Aqueduct of Valens! It’s true that this structure reflects the genius of Roman engineering, and we Turks are proud to have inherited such a rich and diverse legacy from those who came before us. Istanbul’s history is layered with contributions from many cultures, including Greeks, Romans, Byzantines, and Ottomans, all of whom have left their mark.
Some might say that Turks don’t see themselves as mere inheritors but as caretakers of this shared cultural heritage. We respect the history and ensure these marvels are preserved for future generations—whether they are Turkish, Greek, or anyone else. The aqueduct isn’t just a Greek story or a Roman one; it’s a human one, and I think that’s something we can all take pride in!
I appreciate your reply and your perspective on the shared nature of historical heritage. However, I can’t help but notice how the narrative of ‘caretakers’ is often used to sidestep the more uncomfortable truths of history. Let’s be honest—Constantinople was built by Greeks and Romans, and its legacy was defined long before the Ottomans entered the picture. While it’s commendable that these monuments are preserved, it’s also important to acknowledge the erasure of the original cultural and religious identity that came with their ‘inheritance.’
The Aqueduct of Valens, for instance, was not just a ‘human’ achievement; it was a Roman-Byzantine one, part of a city whose roots are undeniably Greek. Preserving it doesn’t erase the fact that much of what stood here—churches, monuments, libraries—was repurposed or destroyed to fit a new narrative. So yes, it’s nice to see these remnants cared for, but perhaps the pride taken in ‘inheritance’ could also be tempered with an acknowledgment of what was lost along the way?
Thank you for sharing your thoughts. I truly appreciate your passion for Constantinople‘s legacy, and I’d like to add that what makes Istanbul—whatever name you prefer—so extraordinary is how it continues to thrive as a city of over 20 million souls. At The Other Tour, that’s what we focus on: the living, breathing energy of this place and the people who call it home today. But make no mistake, we deeply cherish the multi-layered nature of Istanbul‘s history and the way it connects all of us.
Personally, I often find myself yearning for the days when the Greek, the Jew, the Armenian, and the Muslim Turk lived side by side in this great city—not just coexisting, but sharing, laughing, and, yes, probably sinning a little together in the corners of this fascinating place. That’s the Istanbul I dream about, where differences weren’t walls but windows into each other’s lives.
So, while we may come at this history from different angles, I think there’s something beautiful in how we both feel so strongly about it. At the end of the day, we’re all part of this city’s ongoing story, and maybe that’s the most important legacy of all.