A huge city hidden for thousands of years by lush vegetation has been found in the Amazon.
The discovery changes our knowledge about the history of the inhabitants of the Amazon.
The houses and squares of the Upano area of eastern Ecuador were connected by an incredible network of streets and canals.
The area lies in the shadow of a volcano that created rich soils, but may also have led to the destruction of society.
While cities in the highlands of South America, such as Machu Picchu in Peru, were known, people were thought to only live nomadically or in small settlements in the Amazon.
A lidar image of the Upano Valley.
“This is older than any other site we know of in the Amazon. We have a Eurocentric vision of civilization, but this shows that we need to change our idea of what culture and civilization are”, says Prof. Stephen Rostain, director of investigations at the National Center for Scientific Research in France, who led the research.
«It changes the way we see Amazonian cultures. Most people imagine small groups, probably naked, living in huts and tilling the land: this shows that ancient people lived in complicated urban societies,” says co-author Antoine Dorison.
These settlements were built and inhabited between approximately 500 BC and 300-600 AD when the Roman Empire dominated Europe.
It is difficult to accurately estimate the number of people who lived there, but scientists say it was definitely 10,000 people, if not 100,000.
The archaeologists combined the ground excavations with a survey of a 300 km² area using laser sensors flown from an aircraft that can identify the remains of the city under the dense plants and trees.
A Lidar map of the town of Kunguints in the Ecuadorian Amazon reveals ancient streets lined with houses.
LiDAR technology identified 6,000 rectangular platforms measuring approximately 20 by 10 meters and 2-3 meters high.
They were arranged in groups of three to six units around a square with a central platform.
Scientists believe many were homes, but some were intended for ceremonial purposes. One complex, at Kilamope, included a 140 meter by 40 meter platform.
Structures were built by cutting into hills and creating an earthen platform on top.
A network of straight roads and paths connected many of the platforms, including one that stretched for 25 km.
Roads, paths and canals connecting the platforms were found, suggesting that a large area was occupied
Dr Dorison said these roads are the most surprising part of the research. «The road network is very sophisticated. It extends over a vast distance, everything is connected. And there are right angles, which is really impressive,” he said, explaining that it is much more difficult to build a straight road than one that fits the landscape.
He believes that some had a “very strong meaning”, perhaps linked to a ceremony or belief.
The scientists also identified causal roads with ditches on both sides that they say were canals that helped manage the region’s abundant water.
There are signs of possible threats to the cities: some ditches blocked the entrances to the settlements and could be evidence of threats from nearby populations.
Researchers first found traces of a city in the 1970s, but this is the first time a full survey has been completed, after 25 years of searching.
The research reveals a large and complex society, which appears to be even larger than the well-known Maya societies of Mexico and Central America.
Scientists have found evidence of 6,000 mounds thought to underlie ancient dwellings
“Imagine discovering another civilization like the Mayan, but with completely different architecture, land use and ceramics,” says José Iriarte, professor of archeology at the University of Exeter, who was not involved in the research.
Some of the finds are “unique to South America,” he explains, pointing to the octagonal and rectangular platforms arranged together.
The societies were clearly well organized and interconnected, he says, pointing to the long sunken roads between settlements.
Not much is known about the people who lived there and what their societies were like.
Pits and hearths, vases, stones for grinding plants and burnt seeds were found on the platforms.
The inhabitants of Kilamope and Upano probably devoted themselves mainly to agriculture. The people ate corn and sweet potatoes and probably drank “chicha”, a type of sweet beer.
Prof. Rostain says he was warned about this research early in his career, because scientists believed that no ancient groups had lived in the Amazon. «But I’m very stubborn and I did it anyway. Now I must admit that I am very happy to have made such an important discovery,” he says.
The next step for the researchers is to understand what lies in an adjacent 300 km² area that has not yet been detected.