(CNN) — Archaeologists working deep in the Amazon rainforest have discovered an extensive network of cities dating back 2,500 years.

Pre-Hispanic settlements, highly organized, with wide streets, long, straight paths, plazas and groups of archaeological platforms, have been found in the Obano Valley, in the Ecuadorian Amazon, on the eastern slopes of the Andes, according to one study. Stady Published Thursday in the magazine Sciences.

The discovery of the oldest and most extensive urban network of built and excavated items in the Amazon to date was the result of more than two decades of research in the region by a team from France, Germany, Ecuador and Puerto Rico.

The research began with field work before the publication of the so-called remote sensing method lidar (Laser Object Detection and Measurement System), which uses laser light to detect structures under thick tree canopies.

The study's lead author, Stephen Rosten, an archaeologist and director of research at the French National Center for Scientific Research (CNRS), described the discovery as “incredible.”

Advanced engineering

“The lidar gave us an overview of the area and we were able to greatly estimate the size of the sites,” he told CNN on Friday, adding that it showed them a “whole network” of excavated roads. “The lidar was the icing on the cake.”

The first people to live there 3,000 years ago had small, scattered homes, Rustin said.
However, between approximately 500 B.C. and 300 to 600 A.D., Kilomobi and later Obano cultures began building mounds and placing their homes on earthen platforms, according to the study's authors. These platforms are organized around a low square arena.

LiDAR data revealed the presence of more than 6,000 platforms in the southern half of the 600 square kilometers area studied.

According to the study, the platforms were mostly rectangular, although some were circular, and their dimensions were about 20 x 10 meters. They were usually built around a square in groups of three or six. Arenas also usually have a central platform.

The team also discovered massive complexes with much larger platforms, which may have had a civic or ceremonial function.

At least 15 groups of complexes have been discovered that have been identified as settlements.

Some settlements were protected by ditches, while there were roadblocks near some large compounds. According to the researchers, this indicates that the settlements were exposed to threats, whether external or arising from tensions between groups.

Even the most isolated complexes were connected by roads and an extensive network of large straight roads with sidewalks.

In the empty areas between the compounds, the team found features of land cultivation, such as drainage fields and terraces. According to the study, these elements were linked to a network of paths.

“That's why I call them garden cities,” Rustin said, adding: “It's a complete revolution in our model of the Amazon.”

“We have to believe that all the indigenous jungle (peoples) were not semi-nomadic tribes lost in the jungle in search of food. They are a great diversity, diverse statuses, and some of them also had an urban system, with (a) caste society,” he said.

The general organization of the cities indicates “the presence of advanced architecture” at that time, according to the study's authors, who concluded that the garden urbanism of the Obano Valley “provides further evidence that the Amazon is not the pristine jungle it once represented.” “.

Rustin said we should imagine the pre-Columbian Amazon as an “anthill,” where everyone goes about their business.

Similar locations all over the American continent

According to landscape archaeologist Carlos Morales Aguilar, a postdoctoral fellow at the University of Texas at Austin, who was not involved in the study, this newly discovered urban network closely matches other sites found in the tropical forests of Panama, Guatemala, Belize and Brazil. And Mexico.

Morales Aguilar called the study “groundbreaking” and told CNN that it “not only provides tangible evidence of early and advanced urban planning in the Amazon, but also contributes significantly to our understanding of the cultural and environmental heritage of indigenous communities in the Amazon.” ” this area”.

In 2022, Morales Aguilar was part of a team of researchers that used lidar technology to discover a vast site in northern Guatemala, comprising hundreds of interconnected ancient Maya cities, towns and villages, as well as a 177-kilometre network of elevated tracks. Stone structures connecting communities.

The researcher stated that the results of this latest study reflect the advanced agricultural and urban planning techniques he observed in northern Guatemala and “offer new perspectives on the complexities of these primitive societies.”