A “lost valley of cities” has been discovered in the Amazon rainforest that was once home to more than 10,000 farmers around 2,000 years ago.
Experts said the discovery in the foothills of the Andes changed what was known about the history of people in the region. A series of earth mounds and buried roads in the Upano area in eastern Ecuador was first noticed more than two decades ago by archaeologist Stéphen Rostain.
He said that at the time he wasn’t sure how it all fitted together. He was one of the researchers who reported on the find in the journal Science.
Recent mapping by laser-sensor technology revealed those sites to be part of a dense network of settlements distributed in a geometic pattern and connecting roads that lasted about 1,000 years. “It was a lost valley of cities,” said Mr Rostain. “It’s incredible.”
The settlements were occupied by the Upano people between around 500 BC and 300 to 600 AD — a period roughly in line with the Roman Empire, the researchers found.
Residential and ceremonial buildings erected on more than 6,000 earth mounds were surrounded by agricultural fields with drainage canals. The largest roads were 33 feet wide and stretched six to 12 miles.
While it was difficult to estimate populations, the site was home to at least 10,000 inhabitants — and perhaps as many as 15,000 or 30,000 at its peak, according to archaeologist Antoine Dorison, a study co-author at the same French institute.
That was comparable to the estimated population of Roman-era London, then Britain’s largest city.
“This shows a very dense occupation and an extremely complicated society,” said University of Florida archaeologist Michael Heckenberger, who was not involved in the study. “For the region, it’s really in a class of its own in terms of how early it is.”
