Two long-forgotten cities have been discovered in Uzbekistan's southeast, buried for centuries under mountainous terrain.

The urban centers, Tashbulak and Tugunbulak, are located about five kilometers apart and have now been digitally mapped by researchers using LiDAR (Light Detection and Ranging) technology.

Once bustling medieval hubs on the ancient Silk Road, the cities were inexplicably abandoned and left untouched in the mountainous pastures of Central Asia.

Using drone-borne LiDAR technology in the region, archaeologists captured images of the ancient cities, revealing a sprawling urban network with fortresses, plazas, and roads.

Led by Michael Frachetti, an anthropology professor at Washington University in St. Louis, the research marks the first time LiDAR has been deployed in this part of Central Asia. The laser-based technology enabled the team to penetrate thick vegetation, showing the cities' layouts with remarkable detail.

"Up in these mountains, it's like stepping back in time," Frachetti noted. "The sheer scale of the urban layout, at such altitude, is astonishing."

Preliminary excavations of Tugunbulak in 2022 unearthed medieval pottery, indicating active human occupation in the area from as early as the eighth century until the eleventh century.

The newly mapped cities sit over 2,000 meters (6,562 feet) above sea level.

According to the study, only 3% of the world's population lives at such extreme heights today, mostly on the Tibetan Plateau and the Andes.

Living conditions in these high-altitude regions would have been challenging, particularly during the harsh winters, Frachetti explained. However, the highlands offered valuable resources, such as iron ore and dense juniper forests, which likely supported local industries, including iron smelting.

"This environment is vastly different from other Silk Road sites," Frachetti remarked. "We're already getting snow up here in summer—it's a rough place to live."

These conditions highlight the resilience and resourcefulness of the populations who built and sustained these cities.

The study, published in Nature, also notes that the architectural styles of the newly discovered cities differ significantly from more famous Silk Road locations like Samarkand and Kashgar, both of which are surrounded by agricultural landscapes. These differences forced scholars to reevaluate the logistical and social factors that shaped Silk Road civilizations.

Frachetti and Uzbek archaeologist Farhod Maksudov initially found Tashbulak in 2011. Inspired by the local landscape and later assisted by a forester's report of unusual formations, the researchers continued to uncover Tugunbulak in 2015. Their findings reveal that the settlements were significantly larger and more sophisticated than previously thought, suggesting a central role in regional trade and manufacturing.

The LiDAR images of Tugunbulak have revealed a citadel, defensive walls, and a variety of architectural features. In Tashbulak, remnants of dense urban planning and walled fortifications offer further clues to the cities' social and economic dynamics. For Frachetti and his team, the ongoing exploration of these forgotten cities promises to unlock even more secrets from the ancient Silk Road.