Laser technology has revealed more than 20,000 ancient earthworks hidden beneath the Amazon rainforest canopy, rewriting the history of pre-colonial settlement in South America. detikInet reported that aerial surveys covering over 4,400 square kilometers in the Brazilian states of Acre and Amazonas exposed extensive monumental structures previously obscured by dense vegetation.
Researchers combined Light Detection and Ranging (Lidar) with satellite imagery to map the massive footprint of the Aquiry civilization. This large pre-colonial society flourished from around 600 BC to AD 850, occupying an estimated 183,000 square kilometers across modern-day Brazil, Bolivia, and Peru, according to JournalArta.
The findings challenge long-held assumptions that pre-Columbian Amazonia held few inhabitants and remained a pristine wilderness. Scientists now estimate the region supported between 1.25 million and 3 million people at its peak between AD 100 and AD 300, living in complex communities that actively engineered their surrounding environment.
Society members built geometric earthworks and roads
Society members constructed large geometric earthworks featuring deep ditches and high embankments, with some sites connected by wide ancient roads. BBC reported that researchers mapped 350 kilometers of roads linking these structures, noting that pathways widened as they approached major monumental sites.
Excavations and aerial scans show trenches reaching widths of up to 15 meters and depths of five meters.
From 432 Aquiry earthworks identified during the study, only 36 had prior documentation. Researchers estimate there are between 24,000 and 30,000 total features across the study area, with roughly two-thirds belonging directly to the Aquiry civilization before sites were abandoned between AD 850 and AD 950.
Transforming Amazonian Archaeology
Early researchers faced severe visibility limits when studying geoglyphs in deforested areas, leaving forest-covered structures undetected. Lidar technology finally allowed scientists to pierce the dense canopy and reveal the true scale of human modification.
“When I saw some of these monumental geometric structures, now known as Amazonian geoglyphs, on the outskirts of the capital that had undergone deforestation, along with ancient wide roads, I said to Alceu: ‘This is going to change everything we think we know about the Amazon wilderness.’ For me, that was a truly transformative moment,” said Martti Pärssinen from the Instituto Iberoamericano de Finlandia in Madrid, speaking to detikInet.
Pärssinen said that the civilization also managed and cultivated useful Amazonian tree species, including Brazil nut trees and palms such as peach and uricuri.
Ceremonial centers integrated with forest urbanism
“The geometric buildings, roads, embankments, and plazas seem to serve not primarily as fortifications or densely populated cities, but as ceremonial and political centers connected to scattered communities,” said José Miguel Pérez-Gómez, a Venezuelan archaeologist not involved in the study, as quoted by detikInet.
“This is a form of forest urbanism: fragmented, polycentric, and deeply integrated with dark clay, waterways, cultivated plants, and useful species,” Pérez-Gómez explained.
What Lidar is and when Aquiry occupied the region
What is Lidar and how did it reveal the Amazon structures?
Lidar is an active remote sensing technology that uses pulsing laser light to measure distances precisely and create detailed three-dimensional maps. By mounting lasers on aircraft, researchers penetrated the dense forest canopy to detect earthworks invisible to standard aerial photography.
When did the Aquiry civilization occupy the region?
The Aquiry civilization developed around 600 BC and maintained its monumental building practices until approximately AD 850. Communities left the studied earthwork sites between AD 850 and AD 950.
How large was the population of the Amazon during this period?
Researchers estimate that the greater Amazon region supported between 1.25 million and 3 million people at its demographic peak between AD 100 and AD 300. This challenges older models that viewed the basin as incapable of sustaining large complex societies.
Pärssinen said that because the study area represents less than three percent of greater Amazonia, researchers are now questioning what else remains hidden beneath the forest canopy, with findings published in the journal Nature.
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