Archaeologists have uncovered remnants of five cities dating back 2,500 years in the Amazon rainforest, using laser scanning technology. The findings include an intricate network of farmland and roads, marking the most ancient and extensive discovery of its kind in the Americas.
Upano Valley
The expansive site, spanning over 300 square kilometres in the Upano valley of eastern Ecuador, was hidden by the jungle. Stephen Rostain, director of research at the French National Center for Scientific Research led a research team that used LiDAR to uncover the site. Rostain first detected traces of the lost civilisation 25 years ago, when he stumbled upon hundreds of mounds in the area.
In 2015, Rostain and his group of researchers began to use LiDAR to survey the site. LiDAR allowed them to look at the ground hidden below the forest cover without disturbing over cutting down the trees.
The survey discovered a dense system of pre-Hispanic urban centres with more than 6,000 rectangular earthen platforms, primarily interpreted as the foundations of ancient residences, spread across five major settlement clusters and 10 smaller settlements. These are surrounded by agricultural fields and terraces on hillsides.
The interconnected system of roads that links these settlements suggests their simultaneous existence. These cities predate other advanced Amazonian societies, including the recently discovered ancient urban system, Llanos de Mojos, in Bolivia. While the exact population of the Upano Valley settlements remains unknown, the study highlights the extensive size of the settlement density.
Upano Valley civilization is believed to have existed from 500 B.C.E. until 300 to 600 C.E. The residents primarily focused on agriculture, such as growing corn and sweet potatoes. Some of the mounds discovered, are about 10 metres tall, suggesting they were not homes but communal areas for rituals or festivals. According to researchers, these remains are a major discovery as Amazonian settlements were previously believed to practice nomadic lifestyle.
Speaking to the BBC, Prof Stephen Rostainsaid, “This is older than any other site we know in the Amazon. We have a Eurocentric view of civilisation, but this shows we have to change our idea about what is culture and civilisation.”
What is LiDAR?
LiDAR, or Light Detection and Ranging, is a remote sensing technology that employs laser light to measure distances and create precise, three-dimensional representations of the Earth’s surface.
It operates on the principle of sending laser pulses from a sensor to the ground and measuring the time it takes for the light to return. By calculating the round-trip travel time of these pulses, LiDAR systems can determine the distance between the sensor and the target with remarkable accuracy.
LiDAR is widely used for various applications, including topographic mapping, forestry, urban planning, and archaeology. In archaeology, LiDAR has been instrumental in uncovering hidden archaeological features and landscapes by penetrating dense vegetation and capturing detailed terrain data.
This technology allows archaeologists to create detailed, three-dimensional maps of archaeological sites, revealing subtle topographical variations and features that may be concealed by vegetation or natural terrain.