Martti Pärssinen and colleagues identify a massive precolonial civilization in the southwestern Amazon with a population of up to 3 million people.
Archaeologists have discovered that the southwestern Amazon rainforest was home to a massive precolonial civilization known as the Aquiry. Using airborne LiDAR technology, Martti Pärssinen and his team identified nearly 30,000 geometric earthworks, which are deep ditches and high embankments. These structures suggest that the region supported a much larger population than previously thought, with estimates ranging from 1.25 million to 3 million people during the civilization's peak between 100 and 300 C.E. The findings challenge the long-held belief that the Amazon was a pristine wilderness. Instead, the data shows a landscape shaped by humans for centuries, featuring complex geometric designs like circles, squares, and octagons. The Aquiry civilization developed far from major rivers, suggesting high population densities and sophisticated land management. The research indicates that the precolonial Amazon was a highly organized environment where people cultivated crops like maize and squash while building monumental public and ceremonial centers.