A 20-year quest to uncover one of the ancient world's engineering marvels is the focus of a new exhibition in Istanbul.
British archaeologists working with Turkish scientists have revealed a vast water supply system that served the Byzantine city of Constantinople - the predecessor of modern Istanbul.
Now they hope that the exhibition in Istanbul's RCAC Gallery will help bring to life the intricate network of water channels, tunnels and bridges that dates back to the fourth century.
The exhibition - called Waters for a Capital - uses photographs and computer graphics to show how researchers have been able to document these world class monuments for the first time.
Archaeologists say the spectacular remains - mostly hidden in suburban forests or beneath the modern city - are still largely unknown, despite being among the most extensive of their kind.
The system carried fresh water more than 400 kilometres from springs outside the ancient city to the heart of the metropolis, which was created by the Roman emperor Constantine in 330.
Researchers have identified a long distance network of well-preserved channels and bridges that are among the most impressive to survive from the Roman world.
Lead archaeologist Professor James Crow, of the University of Edinburgh, mapped the system with water engineers and remote sensing experts from Istanbul Technical University.
Highlights include one of the world's grandest Roman aqueducts, which is 30 metres high and almost 140 metres in length. Tunnels up to 200km in length have also been identified.
So impressive was the workmanship that the system provided fresh water to the largest city in the ancient world for another 600 years.
Prof Crow, who is based in the School of History, Classics and Archaeology, began his research while working at Newcastle University.
"This exhibition highlights some exceptional ancient monuments that are part of the fabric of Istanbul, yet still relatively unknown to many of its inhabitants. "Istanbul is a growing city with few sources of local fresh water. A greater understanding of how supplies were resourced in the past can inform how the city meets its future needs. "We also hope to encourage greater awareness among conservation bodies in the hope that long-term preservation will bring economic benefits to the area through sustainable tourism."