Hidden Ancient Cities Revealed by LIDAR in the Amazon Rainforest
Recent archaeological breakthroughs have fundamentally changed our understanding of the Amazon. For decades, researchers believed the Amazon rainforest was historically sparsely populated by small, nomadic tribes. However, advanced laser mapping technology has uncovered a sprawling network of ancient cities hidden beneath the dense canopy for thousands of years.
While the Maya civilization is famous for its stone pyramids in Central America, this new discovery in the Amazon reveals a complex, agrarian civilization that rivals the Maya in scale and sophistication.
The Discovery in the Upano Valley
In early 2024, a study published in the journal Science detailed a massive discovery in the Upano Valley of eastern Ecuador. Led by archaeologist Stéphen Rostain from France’s National Center for Scientific Research (CNRS), the team used LIDAR (Light Detection and Ranging) technology to map approximately 300 square kilometers (115 square miles) of the forest floor.
The lasers penetrated the thick vegetation to reveal the ground contours below. What they found was not untouched wilderness, but a dense landscape of human engineering. The scan revealed over 6,000 earthen platforms arranged in geometric patterns. These structures served as the foundations for homes and ceremonial buildings.
A Civilization Built on Earth, Not Stone
Unlike the Maya, who built with limestone in Mexico and Guatemala, these Amazonian builders used the resources available to them: earth and mud. This is why the cities remained hidden for so long. Without stone ruins, the structures looked like natural hills once the jungle grew over them.
Key features of this discovery include:
- Timeline: The sites date back to around 500 BCE and were occupied until roughly 600 CE. This makes them older than many famous Mayan sites.
- Population: Researchers estimate the population could have reached 10,000 to 30,000 people at its peak. This matches the population of London during the Roman era.
- Structure: The scans identified five major settlements and ten smaller ones.
Advanced Engineering and Infrastructure
The most shocking aspect of the Upano Valley discovery is the infrastructure connecting these settlements. The LIDAR images revealed a complex network of roads and canals that suggest a highly organized society.
The Road Networks
The civilization built wide, straight roads to connect their communities. The largest roads were 10 meters (33 feet) wide and stretched for 10 to 20 kilometers.
The construction of these roads required advanced planning. The builders dug down to create a flat surface and built up the sides, ensuring the roads would not wash away during the Amazon’s intense rainy seasons. The straightness of these paths indicates a centralized authority capable of coordinating large labor forces.
Agricultural Management
The inhabitants were not just hunter-gatherers; they were large-scale farmers. The LIDAR maps show distinct agricultural fields with drainage canals surrounding the residential platforms. This system allowed them to manage water runoff and cultivate crops like maize, manioc, and sweet potatoes in the nutrient-rich volcanic soil of the Andes foothills.
LIDAR: The Archaeologist's New X-Ray
This discovery was only possible due to LIDAR technology. Traditional archaeology in the Amazon is incredibly difficult. The vegetation is thick, the terrain is rugged, and digging is slow.
LIDAR works by shooting thousands of laser pulses per second from an aircraft toward the ground. The sensor measures how long it takes for the light to bounce back. By filtering out the pulses that hit leaves and trees, computers can generate a precise 3D map of the forest floor.
This technology has previously been used to map:
- Tikal (Guatemala): Revealing 60,000 previously unknown Mayan structures.
- Angkor Wat (Cambodia): Showing the city was much larger than previously thought.
- Calakmul (Mexico): Uncovering massive urban sprawl in the Maya Biosphere Reserve.
The application of LIDAR in the Amazon proves that the “green hell” described by early European explorers was actually home to “garden cities” that thrived for centuries.
Frequently Asked Questions
Are these cities Mayan? No. The Maya civilization was located in Mesoamerica (Mexico, Guatemala, Belize). These newly discovered cities are in the Amazon basin (South America), specifically Ecuador. However, they share similarities in complexity, population density, and social organization.
Why were these cities abandoned? The exact reason is currently unknown. The Upano Valley sites appear to have been abandoned around 600 CE. Archaeologists speculate that volcanic activity from the nearby Sangay volcano may have played a role, but further excavation is needed.
Can I visit these ruins? Currently, there is very little to see for a tourist. Because the structures are made of earth and covered in dense jungle, they are difficult to identify from the ground without a guide or excavation. The “visual” discovery exists primarily in the 3D maps generated by the computers.
How does this change history? It disproves the long-held belief that the Amazon soil was too poor to support large, complex civilizations. It suggests the pre-Columbian population of the Amazon was in the millions, rather than small isolated bands.