Ancient cities dating back 2,500 years uncovered deep in Amazon rainforest

An extensive network of ancient cities dating back 2,500 years has been uncovered deep in the Amazon rainforest, archaeologists said.

According to a study published in the journal Science on Thursday, the highly structured pre-Hispanic settlements were found in the Upano Valley of Amazonian Ecuador in the eastern foothills of the Andes.

The cities are complete with wide streets, straight roads, large plazas, and monumental platforms.

The discovery is the earliest and largest urban network of built and dug features in the Amazon so far and was the result of over two decades of searches in the region.

A research team from France, Germany, Ecuador, and Puerto Rico deployed a remote sensing method called light detection and ranging, which used laser light to detect structures in the thick Amazon rainforest.

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Stephen Rostain, the lead author of the study and said the discovery was “incredible.”

Rostain said to CNN: “The lidar gave us an overview of the region and we could appreciate greatly the size of the sites. The lidar was the cherry on the cake.”

He added that it gave them a “complete web” of dug roads.

The first people who lived in the cities were there 3,000 years ago and had small houses, Rostain said.

But between 500 BCE and 300 to 600 CE, they began to build mounds and set their houses on earthen platforms, the study showed.

The Amazon rainforest at Amazonas State Brazil

More than 6,000 platforms were found within the southern half of the 232-square-mile area surveyed, according to data from the lidar.

The platforms were typically built around a low, square plaza. The discovery included at least 15 clusters of complexes identified as settlements.

In addition, researchers said signs of threats, either external or between groups, were suggested by ditches in front of settlements.

The team also found features of land cultivation, such as drainage fields and terraces, which were linked to a network of footpaths.

Rostain said: “For that reason, I call this garden cities. It’s a complete revolution in our paradigm about the Amazon.”

He added: “We have to think that all the Indigenous (people) in the rainforest were not semi-nomadic tribes lost in the forest, looking for food.

“They’re a big variety, diversity of cases and some were also with (an) urbanist system, with (a) stratified society.”

The study authors also said the organization of the cities suggests “the existence of advanced engineering” at the time.

Rostain added that pre-Columbian Amazonia should be imagined “like a nest of ants,” with everybody busy.

This marks the latest discovery of ancient sites found across tropical forests, as other sites have been found in Panama, Guatemala, Belize, Brazil, and Mexico.