Archaeologists have uncovered hundreds of vast earthworks in the Amazon rainforest, which they say are evidence of a “lost civilisation” that flourished nearly 2,000 years ago, said New Scientist.
Researchers believe the geometrically patterned structures, known as geoglyphs, were built by an advanced pre-colonial society, known as the Aquiry, between 600BC and AD850 – without metal tools or animals. But they are almost impossible to detect under the dense tree canopy of the deep rainforest.
The scientists used cutting-edge airborne laser scanning technology and found hundreds of previously unknown earthworks. They combined the light detection and ranging (LiDAR) data with previous findings to estimate that there might be up to 30,000 structures across the Aquiry territory. The results “strongly suggest” that at its peak, the civilisation may have numbered 1.25 to 3 million, they wrote in a study published in Nature.
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‘Astonishing’ scale and precision
Indigenous people have known about some of the earthworks for generations, “regarding some as sacred”, said The Times. Archaeologists first identified several in the western Brazilian state of Acre in 1977, when deforestation began to clear parts of the forest. In 2003, archaeo-anthropologist Martti Pärssinen, from the University of Helsinki, and his team flew overhead and observed ancient straight roadways connecting the sites, in a region that had long been regarded as “virtually untouched”.
“It was a common idea that the Amazonian forest was a virgin wilderness, occupied only by small groups of hunter-gatherers,” said Pärssinen, the study co-author. “These earthworks totally change our understanding of the supposedly pristine Amazon.”
Pärssinen theorised that the earthworks had been built by a complex, pre-Columbian civilisation. In 2021, he “officially introduced the name Aquiry”, said LiveScience, after the Indigenous name for the Acre River, which flows from Peru and Bolivia into Brazil.
In 2024, his team used aerial photographs and satellite imagery to count nearly 1,300 structures across southwestern Amazonia. But “the full scale remained lost beneath the trees”, said ScienceAlert. LiDAR technology “changed everything”.
The team flew over around 1,700 square miles, firing rapid laser pulses at the ground. Some pulses penetrate gaps in the forest canopy and bounce off the ground, reflecting back to the sensors. Computers can use that to create “a three-dimensional map of the ground under most vegetation”, said New Scientist.
The survey revealed 432 geoglyphs – “nearly 400 of which were completely new to science”. The largest covered an area of nearly 50 hectares. “The scale and precision of these constructions is simply astonishing,” said Pärssinen. An average-sized geoglyph would have required about 300 people to build and maintain it.
Pärssinen’s estimate of a population of up to 3 million people is bold, said Michael Heckenberger, from the University of Florida, but “plausible and extremely important, even mind-blowing”.
They lived ‘in harmony with the forest’
Over the past two decades, LiDAR has become “one of archaeology’s most exciting modern tools”, said National Geographic. It has been credited with driving an “archaeology revolution”. In the early 2010s, archaeologists were “astonished” when it revealed a lost Maya city.
But we still don’t know much about the Aquiry – they left “no written records, and their dwellings are long gone”, said ScienceAlert. We don’t know why they suddenly disappeared, between about AD850 and 1000. But the findings suggest that the view of the Amazon as a practically untouched wilderness should be “abandoned”, said Pärssinen.
The presence of thousands of geoglyphs is “leading archaeologists to rethink assumptions about pre-colonial civilisations and urban development”, said LiveScience.
While Romans were “laying roads and building temples”, the Aquiry were “carving vast circles, squares and monumental enclosures” on the other side of the world, said The Times. Their territory extended across “an area slightly smaller than Britain”. And the geoglyphs suggest “sophisticated planning and organised labour”.
Pärssinen said the civilisation is “likely to have resembled ancient Greece”: dispersed communities with shared beliefs and traditions, rather than a single centralised empire. The “great enclosures” appear to have been “ceremonial and political centres” where communities met to “make decisions, feast and perform rituals”.
The Aquiry also cultivated maize, squash and manioc, grew Brazil nut trees and peach palms, and cleared forests for the huge earthworks and extensive roads, “without destroying the Amazon”.
“They lived in harmony in that way with the forest,” said Pärssinen. “They made clearings, but not too big to change the ecological systems. Despite their huge numbers, they never converted the rainforest into savannah.”
