Drone-mounted lidar helped reveal Tashbulak, a 12-hectare city near Tugunbulak
SAIElab, J. Berner, M. Frachetti
More than 2000 metres above sea level, on a grassy mountain plateau in eastern Uzbekistan, two archaeologists out for a stroll discovered something astonishing. This chilly, wild landscape was once home to two sprawling cities, whose markets bustled with travellers from the Silk Road trade routes that linked China to the West. All that was left of these millennia-old communities were thousands of pottery shards, scattered across the plateau – and the heavily eroded earth mounds and troughs that marked where buildings, walls and roads once stood.
Luckily, researchers Farhod Maksudov at the Uzbekistan Academy of Sciences and Michael Frachetti at Washington University in St Louis, Missouri, were able to uncover the cities’ lost infrastructure without lifting a single shovel. They did it with drone-mounted lidar, a remote sensing system that uses lasers to create 3D maps of terrain.
Analysis revealed Tashbulak, a 12-hectare city about 5 kilometres from Tugunbulak, which occupied a whopping square kilometre-plus. In a paper out this year, scholars described the citadels, plazas, industrial workshops devoted to metallurgy, and high-density housing of the twin sites. Their existence challenged many long-held beliefs about the locations of central Asian trade routes over a thousand years ago.
2024 was a banner year for ancient historical discoveries made possible by such methods. Archaeology graduate student Luke Auld-Thomas at Tulane University in Louisiana published a paper about how he found one of the biggest Mayan cities in Latin America. He did it from his computer, using lidar data from a survey done in the Mexican state of Campeche years earlier.
This ancient, deserted metropolis, dubbed Valeriana, lies deep in the heart of a tropical forest. It had elevated causeways, ball courts for sporting events, plazas, terraced farms, a dam and a deep reservoir. Lidar is the perfect tool for discerning features hidden by vegetation, and the city today is entirely obscured by jungle. But back in the 8th century, the inhabitants used their ingenuity to convert such an environment into an urban paradise, with room for nearly 50,000 people.
Valeriana’s heyday was around the same time that Silk Road traders were streaming through Tashbulak and Tugunbulak, probably snacking on dumplings. (Yes, there is ample evidence that Silk Road travellers ate such fare.) The connections forged with these ancient cities gave rise to cross-cultural traditions and long-distance commercial relationships whose sophistication might rival those urbanites experience today.
It is also possible that Valeriana and the twin cities of Tashbulak and Tugunbulak were abandoned due to problems that many modern people would recognise with a groan. Auld-Thomas and his colleagues suggest that climate change may have led to droughts that made Valeriana unsustainable at such a large population size. And the fortunes of Silk Road cities rose and fell with the political empires that controlled supply chains across the trade network. When profits dried up, the city slickers of medieval Uzbekistan may have left for greener pastures.
A thousand years on, many of us once more face climate change and political instability. What high-tech archaeology reminds us is that we aren’t the first people to live through such times. If our ancestors survived them, so can we.
Annalee Newitz is a science journalist and author. Their latest book is Stories Are Weapons: Psychological warfare and the American mind. They are the co-host of the Hugo winning podcast Our Opinions Are Correct. You can follow them @annaleen and their website is techsploitation.com
Topics:
