Archaeologists Have Discovered Massive Lost Cities In the Amazon Jungle

Researchers have discovered multiple lost 2500-year old cities deep within the jungles of the Amazon. The highly complex organization of this city network is unlike anything uncovered before, and radically changes our view of ancient Amazonian culture.

Historically, Amazonian cultures were thought of in the West as primitive and nomadic, or only being capable of building simple settlements. It wasn’t until the 1980s that archaeologists found thick layers of dark earth along the Amazon river that this view started to change. Even then, researchers squabbled well into the 2020s over whether these were made by floods or people. 

“We decided they were savage and this image was perfect for us,” Stéphen Rostain, co-author and archeologist at the National Center for Scientific Research in Paris, told Motherboard. “This became our official history.”

This latest finding—the culmination of more than 20 years’ work—details at least 15 sites totalling 6,000 structures all intricately connected by a series of roads. Together, the researchers say the sites make up a network of ancient Amazonian cities. They’re described in the journal Science.

Researchers identified clusters of buildings resembling residential areas, as well as huge ceremonial complexes, spanning a 300 square kilometer area in the foothills of the Andes known as the Upano Valley. They also found ditches and blocked-off roads, which the authors interpreted as defenses against rival groups. Surrounding the platforms are a series of fields and terraces, connected by drainage canals and dug out footpaths.

They were able to glimpse the ancient structures using a canopy-penetrating visualization technology called LIDAR, which shoots a laser from an aircraft and maps the earth’s surface based on how quickly the light bounces back.

Compared to other sites researchers have found, this latest discovery is on “another scale”, the authors write. “The others are not really towns. In the Upano Valley we have a series of cities,” Rostain said. “They completely modified the valley at a level we’ve never seen. It’s incredible.”

One particularly interesting feature Rostain and his team discovered was how near-perfectly straight the roads were. Instead of winding around the natural curves of the valley, they were dug up to five meters deep and intersected at 90 degree angles. Rostain thinks this may indicate that the roads were used for ceremonial reasons, or proscessions. 

Rostain’s team also previously excavated sites within the valley and found floors, hearths, large jars and grinding stones. And an analysis of the grains found in pottery revealed that this ancient culture ate maize, cassava and sweet potato. Researchers even found evidence that the Amazonians made beer.

“This changes the way we see Amazonian cultures,” study co-author and colleague Antoine Dorison told the BBC. “Most people picture small groups, probably naked, living in huts and clearing land. This [discovery] shows ancient people lived in complicated urban societies.”

Dorison, Rostain and their collaborators say their work goes to show how much the Amazon, and its people, have been underestimated. “We believe that it is crucial to thoroughly revise our preconceptions of the Amazonian world and, in doing so, to reinterpret contexts and concepts in the necessary light of an inclusive and participatory science,” the authors conclude.

They’ll continue their work and still have a wealth of data to analyze. “The area is so rich. We’ve only done the tip of the iceberg,” said Rostain.