Lasers reveal massive, 650-square-mile Maya site hidden beneath Guatemalan rainforest

Researchers discovered a large Maya site while surveying northern Guatemala from the air.

A vast Maya site measuring roughly 650 square miles (1,700 square kilometers) and dating to the Middle and Late Preclassic era has been found by geologists in northern Guatemala. (roughly 1000 B.C. to 250 B.C.).

The results came from an aerial study that researchers carried out from an aircraft using lidar (light detection and ranging), a technique that uses lasers to beamed out into the terrain and the reflected light to produce aerial images. Since lasers can pass through dense tree canopies, the technology is especially useful in places like the jungles of Guatemala's Mirador-Calakmul Karst Basin.

The team discovered more than 1,000 villages scattered throughout the area using information from the images. These settlements were linked by 100 miles (160 kilometers) of causeways, which the Maya most likely traveled on foot. The research, which was released on December 5 in the journal Ancient Mesoamerica, also found evidence of a number of huge platforms and pyramids, as well as waterways and water gathering reservoirs.

The lidar data revealed "for the first time an area that was integrated politically and economically, and never seen before in other places in the Western Hemisphere," study co-author Carlos Morales-Aguilar, a postdoctoral fellow in the Department of Geography and the Environment at the University of Texas at Austin, told Live Science in an email. Here in this part of Guatemala, "we can now see the entire landscape of the Maya region," he said.

So what was it about this area that attracted the Maya to reside there in the first place?

According to research co-author Ross Ensley, a scientist with the Institute for Geological research of the Maya Lowlands in Houston, the Mirador-Calakmul Karst Basin was the "Goldilocks Zone" for the Maya. "The Maya inhabited this area because it contained the ideal proportion of uplands for habitation and plains for cultivation. Their main supply of building material, limestone, could be found in the uplands, along with dry ground for habitation. The lowlands are primarily composed of seasonal marshes, or bajos, which offered room for wetlands cultivation and organically rich soil for terraced farming.

Lidar has previously been used by researchers to survey Maya ruins in Guatemala. Two substantial studies of the southern part of the basin, concentrating on the historic settlement of El Mirador, were carried out in 2015 by a project known as the Mirador Basin Project. According to the research, that effort resulted in the mapping of 658 square miles (1,703 square km) of this region of the country.

Morales-Aguilar remarked, "I was blown away when I produced the first bare-earth models of the ancient settlement of El Mirador. The large number of lakes, enormous pyramids, slopes, living areas, and tiny mounds were intriguing to see for the first time.

Researchers are hoping that laser technology will enable them to investigate parts of Guatemala that have been uncharted for many years.

The Middle American Research Institute director at Tulane University and anthropologist Marcello Canuto told Live Science that lidar has been "revolutionary" for archaeology in this region, particularly if it's covered in tropical forest where visibility is constrained. "When measuring, we typically only see a tiny portion of the bridge, but lidar enables us to see large, linear objects. We can now see the area for the first time thanks to this study; having this info is revolutionary.