Laser Mapping Exposes Ancient Amazonian Earthworks

Airborne lasers have revealed a hidden network of hundreds of geometric earthworks beneath the Amazon rainforest, showing that a pre-Columbian civilization once transformed a vast swath of the region. Researchers using LiDAR—light detection and ranging—mounted on aircraft fired laser pulses through dense tree cover to map the ground, uncovering 396 previously unknown structures across a 4,497-square-kilometer area of southwestern Brazil.

The structures are part of the Aquiry culture, which flourished between roughly 600 BCE and 850 CE. The newly found earthworks include ditches and embankments laid out as squares, rectangles, circles, and nested rectangular enclosures linked by broad, straight roads. One particularly striking complex, called D. Schaan, features a monumental nested enclosure connected to multiple perfectly square compounds via wide causeways.

Based on the density of these finds, researchers estimate that the broader 183,000-square-kilometer territory once occupied by the Aquiry people could hold between 24,000 and 30,000 such monuments. At its peak, around 100–300 CE, the civilization may have numbered 1.2 million to 3 million people—making it one of the largest known pre-Columbian societies in the Amazon. The study was published in the journal Nature.

What the Discovery Tells Us About Pre-Columbian Amazonia

The findings challenge the longstanding notion of the Amazon as an untouched wilderness before European contact. Instead, they paint a picture of a landscape extensively shaped by large, interconnected communities. Martti Pärssinen, Professor Emeritus at the University of Helsinki, noted that if similar results emerge elsewhere in the Amazon, long-standing assumptions about past human influence on the rainforest’s ecology would need fundamental reassessment.

How LiDAR Is Rewriting History

LiDAR has become a transformative tool in archaeology, especially in heavily forested regions where satellite imagery and ground surveys miss large-scale features. By penetrating the canopy, it produces high-resolution terrain models that reveal earthworks invisible to the naked eye. In this case, the technology showed that a landscape reclaimed by jungle after the civilization’s decline around 850 CE still holds clear traces of human engineering.

Researchers believe the earthworks served as ceremonial and public gathering centers, likely surrounded by longhouses and cultivated fields growing maize, manioc, and squash. Even the surrounding forests were managed, with fruit- and nut-bearing trees deliberately maintained. Many questions remain, including why the society disappeared between 850 and 1000 CE—a puzzle that future LiDAR surveys and ground excavations may help solve.

Why This Matters for Future Amazon Research

The study, published in Nature, could spur increased funding for LiDAR-based archaeological surveys across the Amazon. Such initiatives may influence land-use policies, as evidence of widespread human occupation might strengthen arguments for indigenous land rights and conservation efforts. For the technology sector, the findings highlight the commercial value of aerial remote sensing in environmental and heritage management, potentially opening new markets for LiDAR service providers and data analytics firms.