In a groundbreaking discovery, archaeologists have uncovered traces of 2,500-year-old cities hidden in the Ecuadorian Amazon using laser scanning technology. The find, situated in the Upano Valley, challenges long-held historical beliefs about the region and reveals an extensive network of settlements and roads.

The revelation comes after over two decades of research in the region, but it wasn’t until the Ecuadorian government employed lidar technology that the full extent of the ancient urban centers became apparent. Lidar, a remote sensing technology using lasers, allowed researchers to penetrate the dense Amazon rainforest and unveil a complex system of pre-Hispanic structures.

Lead author of the study, Stéphen Rostain, and director of research at the French National Center for Scientific Research, expressed his amazement at the scale of the results. The lidar survey, covering approximately 300 square kilometers, exposed more than 6,000 rectangular earthen platforms, agricultural terraces, and drainage systems, forming at least 15 distinct settlements connected by a sophisticated network of wide, straight roads.

Co-author Antoine Dorison highlighted the complexity of the society, especially evident in the carefully constructed road network that crossed at right angles rather than following the natural landscape. The researchers estimate that these ancient cities, likely occupied by people from the Kilamope and Upano cultures, existed from 500 B.C.E. until 300 to 600 C.E. The residents were primarily engaged in agriculture, cultivating crops like corn and sweet potatoes.

This discovery challenges previous assumptions that ancient South Americans lived nomadically or in tiny settlements in the Amazon. Contrary to these beliefs, the newly unearthed cities are estimated to have housed populations in the tens of thousands, if not hundreds of thousands. Christopher Fisher, an archaeologist at Colorado State University, describes this as a “paradigm shift” in understanding the extensive occupation of these areas.

Lidar technology has proven instrumental in uncovering ancient Amazonian cities, allowing for more accurate mapping in a fraction of the time compared to traditional methods. The ability to bypass the density of the forest has led to transformative findings in Bolivia, Brazil, Belize, and now Ecuador.

The discovery of these ancient cities serves as a vivid example of the underestimation of the Amazon’s cultural heritage, challenging preconceptions and emphasizing the need for a thorough revision of our understanding of the Amazonian world. As researchers continue to push the boundaries of exploration, the Amazon reveals its twofold heritage: environmental and cultural, including its rich Indigenous history.