Laser Mapping Reveals Oldest Amazonian Cities, Built 2500 Years Ago
3rd January 2025
Archaeologists once believed the ancient Amazon rainforest was an inhospitable place, sparsely populated by bands of hunter-gatherers. But the remains of enormous earthworks, pyramids, and roads from Bolivia to Brazil discovered over the past 2 decades have proved conclusively that the Amazon was home to large, complex societies long before European colonizers arrived. Now, there’s evidence that another human society—the oldest yet—left its mark on the region: A dense network of interconnected cities, now hidden beneath the forest in Ecuador’s Upano Valley, has been revealed by the laser mapping technology called lidar. The settlements, described today in Science, are at least 2500 years old, more than 1000 years older than any other known complex Amazonian society.
Lidar, which allows researchers to see through forest cover and reconstruct the ancient sites below, “is revolutionizing our understanding of the Amazon in pre-Columbian times,” says Carla Jaimes Betancourt, an archaeologist at the University of Bonn who wasn’t involved in the new work. Finding such an ancient urban network in the Upano Valley highlights the long-unrecognized diversity of ancient Amazonian cultures, which archaeologists are just beginning to be able to reconstruct.