LiDAR reveals over 20,000 pre-Columbian earthworks in southwest Amazonia

A new LiDAR survey using canopy-penetrating technology has found that the northern part of southwestern Amazonia alone contains as many earthworks as previously estimated for the entire Amazon basin — more than 20,000 structures. The finding implies that the scale of ancient human settlement in the region was far larger than previously thought. The results were published in the journal Nature.