An ancient Maya settlement, lost to the forest for centuries, was unexpectedly discovered by a Ph.D. student who fell down an internet rabbit hole.
Tulane University Ph.D. candidate Luke Auld-Thomas was more than a dozen pages into Google search results when he came across a laser survey conducted in Mexico by CartoData for environmental monitoring purposes.
Published in the journal Antiquity, Auld-Thomas and his colleagues reported the discovery of an ancient Maya site hidden within neglected LiDAR data, buried at the bottom of a Google search query.
LIDAR Discovery
While advances in remote sensing technology have transformed archaeology over the last two decades, Maya archaeology is often imagined as the result of laborious expeditions through dense jungle terrain in search of long-lost ruins. Instead, Auld-Thomas made a major discovery from the comfort of home.
LiDAR creates a 3D map by firing laser pulses at a landscape from above using drones, aircraft, or other aerial platforms. In this case, the original survey data showed only a dense forest canopy, making the site indistinguishable from the surrounding terrain. However, once that upper layer was digitally removed, a sophisticated settlement came into view.
Located in Mexico’s southeastern state of Campeche, the lost city contains plazas, causeways, ball courts, and pyramids that had remained unseen for centuries. Although the LiDAR operators were focused on environmental monitoring and did not investigate the data at this level, Auld-Thomas and a colleague recognized the archaeological significance of what they were seeing and identified the site, naming it Valeriana.
Valeriana
During their classic period, between 250 and 900 AD, the Maya developed the rugged Campeche landscape into complex urban environments.
The city of Valeriana, which the team found in the data, turned out to be the second-largest Maya site in North America, eclipsing Calakmul, some 100 kilometers distant. According to the researchers’ estimate, 30,000 to 50,000 people resided in the city between 750 and 850 AD, and it possibly served as a regional capital.
The site’s tropical setting has been a subject of debate among archaeologists, who question whether the population density of typical tropical settlements is skewed by the overrepresentation of large, dense settlements in the data. The team’s discovery of a dense and sophisticated urban environment comprised of nearly 7,000 buildings suggests that such dense sites are not unusual.
While the site contains many features typical of Maya cities, one unusual element particularly intrigued the researchers, consisting a sinkhole leading to a partially collapsed cave system, surrounded by a narrow quatrefoil-shaped ditch—a form frequently used in Mesoamerican art to symbolize caves and sinkholes.
Because the feature lacks substantial embankments and is relatively small in scale, the team does not believe it served a defensive purpose. However, its unusual design may warrant further investigation.
LiDAR Discoveries
Remote-sensing technologies such as LiDAR have transformed archaeology in recent decades, allowing researchers to identify hidden sites across vast and inaccessible landscapes without setting foot on the ground.
In 2013, LiDAR surveys revealed extensive urban networks surrounding Cambodia’s Angkor region, once the heart of the Khmer Empire. Researchers later used the technology to digitally strip away the Guatemalan rainforest canopy, uncovering more than 60,000 previously unknown structures. Using traditional survey methods, discoveries on that scale would likely have taken generations to achieve.
Remarkably, Valeriana itself has yet to be surveyed in person. At present, LiDAR imagery remains the only detailed view of the site. The researchers note that field investigations in Mesoamerica rarely result in fewer structures being identified than LiDAR suggests. In many cases, apparent false positives are offset by previously overlooked features discovered during ground surveys.
For now, Valeriana remains concealed beneath the forest canopy much as it has been for centuries. The researchers hope these remote sensing technologies will reveal more such hidden sites in the coming decades; if funding is sufficient to cover more area with drone-based LiDAR systems, they are almost certain that more discoveries similar to Valeriana could await discovery.
The paper, “Running Out of Empty Space: Environmental Lidar and the Crowded Ancient Landscape of Campeche, Mexico,” appeared in Antiquity on October 29, 2024.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.