Thousands of Ancient Structures May Be Undiscovered in the Amazon

According to researchers, there may be more than 10,000 undiscovered pre-Columbian archaeological sites hidden in the Amazon rainforest. This conclusion was reached after surveying only a fraction of the vast rainforest, adding to the growing evidence that the region has been significantly altered by Indigenous societies over the past 12,000 years.

Using lidar technology, Luiz Eduardo Oliveira e Cruz de Aragão and his colleagues surveyed 5315 square kilometers of the Amazon. Lidar uses reflected laser light to create a 3D representation of a landscape, revealing slight variations in topography and uncovering archaeological sites. In this study, 24 previously unknown earthworks were discovered, believed to be remnants of civilizations that existed between 1500 and 500 years ago.

The findings include a fortified village in the southern Amazon, a region known for its dense population and interconnected earthworks. Defensive and ceremonial sites were also identified in the southwestern Amazon, as well as permanent settlements and ceremonial sites with large stone structures arranged in circular clusters in the northern Amazon.

Although the survey covered only a small portion of the Amazon, a computer model was used to predict the number of hidden sites based on the concentration of earthworks in the new data and previously discovered sites. The model estimated that between 10,272 and 23,648 undiscovered earthworks may lie beneath the forest canopy.

The study also revealed that the Indigenous societies that occupied the Amazon were larger than previously thought, at some point numbering up to 5 million people. Evidence of domesticated plants close to the archaeological sites suggests that these lost societies significantly altered the rainforest’s composition. This challenges the notion of the Amazon as a pristine ecosystem and has implications for predictions about its adaptation to climate change.

Michael Heckenberger, an expert at the University of Florida, highlights the importance of recognizing the massive societies that existed in the Amazon before European colonization. Protecting the rainforest, which has already lost 17% of its land, is paramount for the survival of Indigenous peoples and the preservation of their heritage.