In late July 2026, the journal Nature published a study that significantly alters our understanding of pre-European Amazonian history. An international team of scientists employed LiDAR technology – aerial laser scanning capable of penetrating dense vegetation. Within hours of flights over the forest canopy in the Brazilian states of Acre and Amazonas, they were able to “see” what had remained hidden for decades.
The researchers surveyed approximately 4430 km and covered an area of 4497 km². The results are impressive: out of 432 discovered earthworks (geoglyphs and other earthen constructions), only 36 were previously known. These geometrically precise ditches, mounds, and enclosures – circular, square, and polygonal – were constructed starting around 600 BCE and used until 800–850 CE. Some ditches reached widths of 9–13 meters and depths of up to 5 meters. Many structures were organized into clusters, connected by roads, and apparently served as ceremonial and political centers for temporary gatherings of people from different groups, rather than permanent settlements.
Previously, approximately 1300 similar objects had been found using satellite imagery and aerial photography in the northern part of southwestern Amazonia. New LiDAR data allowed for extrapolation: in this region alone, there could be between 20 and 30 thousand earthworks spread across an area of about 183 thousand km². This is comparable to previous estimates for the entire Amazon basin. Scientists refer to this culture as “Aquiry,” named after a river flowing in the area of the discoveries.
During its peak period, around 100–300 CE, the region's population, according to conservative estimates, could have reached 1.25–3 million people, and considering the limits of laser penetration, up to 3.8 million. People practiced slash-and-burn agriculture, cultivating corn, squash, fruit trees (including the peach palm), and actively transformed the landscape. The construction of such large-scale structures required sophisticated labor organization, knowledge of geometry, and long-term planning.
LiDAR not only added hundreds of new points to the map but also revealed that many geoglyphs are surrounded by additional outer mounds, previously unnoticeable. In the Purus and Juruá interfluves, the density of structures was lower, suggesting possible “buffer zones” between different groups. However, on the riverbanks, for example, in the Carauari region, discoveries continue.
These findings fit into a growing body of data that is changing the image of the Amazon: instead of a “virgin forest,” we see an anthropogenic landscape shaped by millennia of human activity. If similar population densities are confirmed in other parts of the basin, estimates of the total pre-European population of the region, human impact on soils, biodiversity, and even global climate models will need to be revised.
LiDAR technology, which has already revolutionized our understanding of the Maya and other cultures, once again proves its power. Beneath the dense green canopy of the Amazon, many secrets still lie, and each new flight could reveal another chapter of forgotten history. For now, the discoveries in southwestern Amazonia remind us: even in the seemingly most explored corners of the planet, nature and time can hold astonishing evidence of the human past.
