Archaeologists Map Two Forgotten Medieval Cities That Flourished Along the Silk Road in the Mountains of Central Asia

High in the mountains of Uzbekistan, archaeologists have mapped the footprints of two medieval cities that thrived along the Silk Road more than 1,000 years ago.

The team of researchers—led by Michael Frachetti, an archaeologist at Washington University in St. Louis, and Farhod Maksudov, director of Uzbekistan’s National Center of Archaeology—found evidence of the cities during foot surveys before scanning the land with lidar equipment attached to drones.

The settlements, Tashbulak and Tugunbulak, are “among the largest ever documented in the mountainous parts of the Silk Road,” according to a statement from Washington University. The researchers published their findings this week in the journal Nature.

“These would have been important urban hubs in central Asia, especially as you moved out of lowland oases and into more challenging high-altitude settings,” says Frachetti in the statement.

The Silk Road wasn’t a traditional road. Instead, it was a general network of trade routes that stretched between Europe and the Middle East to East Asia. Named for the luxurious Chinese fabric that frequently traveled it, the road’s heyday lasted from around 130 B.C.E. to 1453 C.E. Previously, experts assumed that its trading routes passed only through lowlands. But in reality, traders “were dragging the caravans to the mountains,” as Maksudov tells the New York Times’ Alexander Nazaryan.

Tashbulak and Tugunbulak are located more than 6,500 feet above sea level in the mountains of southeastern Uzbekistan. They flourished into major urban centers due to their iron ore, animals and other precious resources, according to the study.

The researchers first came upon remains of Tashbulak while trekking through the mountains in 2011, when they noticed pottery shards, burial sites and mounds of earth scattered throughout the landscape, per Scientific American’s Allison Parshall. A few years later, during excavations of Tashbulak, they met a landowner who had noticed similar pottery shards in his own backyard a few miles away.

“Sure enough, he’s living on a medieval citadel,” Frachetti tells Scientific American. This second site—Tugunbulak—featured similar mounds. “We’re like, ‘Oh my gosh, this place is humongous.’”

At first, Tugunbulak’s true scale evaded the researchers. As they write in the study, “To the naked eye, the modern surfaces of Tashbulak and Tugunbulak appear as grassy, undulating fields with large, pyramidical mounds and sparse surface ceramics as the only indicators of their archaeological character.”

To adequately take stock of both sites, the team pushed to get permission to use drone equipment in Uzbekistan, which enforces strict restrictions on the technology. In 2022, Frachetti and his team finally conducted their surveys, using a lidar-equipped drone to collect millions of data points at Tashbulak and Tugunbulak, per the Times.

“The final high-res maps were a composite of more than 17 drone flights over three weeks,” says Frachetti in the statement. “It would have taken us a decade to map such large sites manually.”

The scans captured the cities down to the centimeter, which allowed researchers to build detailed 3D models. Computer scientists then used computational algorithms to analyze the models and approximate the cities’ bygone architecture and organization.

Despite their high elevation and harsh climate, Tashbulak and Tugunbulak weren’t simply outposts or rest stops, but cities with their own economies. Preliminary excavations have already revealed that Tugunbulak contained a fortress with walls nearly ten feet thick—possibly a factory where smiths converted iron ore to steel.

The team thinks Tashbulak existed between roughly 730 C.E. and 1050 C.E. with a population in the thousands, while Tugunbulak existed between 550 C.E. and 1000 C.E. with a population in the tens of thousands, reports Reuters’ Will Dunham.

The Silk Road’s trading networks were “very, very fluid,” as archaeologist Sanjyot Mehendale, chair of the Tang Center for Silk Road Studies at the University of California, Berkeley, tells Scientific American. Societies like Tashbulak and Tugunbulak ultimately became integral to “a network that stretched all across Eurasia,” she adds. “You can no longer look at these areas and perceive them as remote or less developed.”

Looking ahead, Frachetti hopes to continue investigating high-altitude settlements along the ancient trading network. “We could really change the map of urban development in medieval Asia,” he says in the statement.

“The Silk Road wasn’t just about the endpoints of China and the West,” he adds. “Major political forces were at play in Central Asia. The complex heart of the network was also a driver of innovation.”

Sonja Anderson | READ MORE

Sonja Anderson is a writer and reporter based in New York City.