Lidar reveals lost cities in the Amazon

A lidar map of the city of Kunguints in the Ecuadorian Amazon reveals ancient streets lined with houses. (Image: Antoine Dorison and Stephen Rostain)

Archeologists have discovered a vast and highly complex system of ancient cities dating back nearly 3,000 years in the Amazon rainforest. Complete with a complex network of farmland and roads, the discovery is the oldest and largest of its kind in the region.

Located in Ecuador’s Upano Valley, the structures lie in the eastern foothills of the Andes mountains, according to a study published in the journal Science. After more than 20 years of research, the ancient urban centers were only discovered when the Ecuadorean government employed lidar technology.

“I have explored the site many times, but lidar gave me another view of the land,” archaeologist Stéphen Rostain, lead author of the study and director of research at the French National Center for Scientific Research (CNRS), told Live Science. “On foot, you have trees in the way, and it’s difficult to see what’s actually hidden there.”

A team of researchers from France, Germany, Ecuador and Puerto Rico conducted a lidar survey that covered roughly 300 km². The survey revealed a landscape full of organized human activities, including more than 6,000 rectangular earthen platforms, as well as agricultural terraces and drainage systems.

According to the study, these structures formed at least 15 distinct settlements, which were connected by a system of wide, straight roads. Co-author Antoine Dorison, an archaeologist at the CNRS, said that this society’s complexity is especially evident in this web of streets, which were carefully constructed to cross at right angles rather than follow the landscape.

In recent years, lidar has been a vital tool for discovering traces of ancient civilizations. Lidar allows researchers to survey densely forested areas that are difficult to explore on foot and allows for the creation of accurate maps in a fraction of the time.

In August 2023, a team of researchers in a biological preserve in Mexico’s Campeche State used airborne lasers to cut through dense vegetation. This revealed ancient structures and human-modified landscapes beneath, including pyramids, palaces, and a ball court. The team was able to explore the dense area safely and identified the ancient Mayan city they discovered as Ocomtún.