Recent archaeological findings in Upano Valley of eastern Ecuador have revealed a sprawling 3,000-year-old urban landscape, upending long-held theories that ancient Amazon-dwellers were merely small groups of nomadic hunter-gatherers.
The site, known as Huapula Site, features a massive network of nearly 7,500 man-made structures, including 5,000 earthen platforms, 1,500 hills, and hundreds of rounded mounds known locally as tolitas or montículos, reports BBC.
This complex system, situated under Sangay volcano, was first studied in 1978 by Jesuit priest Pedro Porras, who spent over 200 days excavating the valley.
The true scale of the site only emerged recently using Light Detection and Ranging (Lidar) technology.
In July 2015, the Ecuadorian National Institute for Cultural Heritage (INPC) mapped a 600 sq km area using laser pulses that penetrated the dense jungle canopy to create intricate 3D maps of the ground.
A unique form of urbanism
Experts describe the discovery as a “low-density and multicentric” form of urbanism unique to Amazon. Michael Heckenberger, an anthropologist at University of Florida, characterised it as “urbanism without cities,” noting that it represents an alternative to European city-based models.
The earthen platforms are typically organised in patterns of three to six units around a central plaza.
While smaller mounds served as residential bases – indicated by remnants of jars and cooked seeds – larger structures, some reaching 8 metres in height, likely served ceremonial purposes.
Stéphen Rostain, director of investigation at French National Centre for Scientific Research, noted that the networks were connected by a sophisticated road system.
These straight paths, arranged in an “almost perfect” checkerboard pattern, were between 2 and 15 metres wide and could run for 25km.
Evidence of agricultural fields with drainage canals suggests the cultivation of maize, beans, manioc, and sweet potato.
Debates and unanswered questions
Despite the findings, the site remains an unfinished puzzle. Alden Yépez, an expert from Pontificia Universidad Católica de Ecuador (Puce), and geographical engineer Jonathan Panimboza Deleg theorise that the trenches may have functioned as drainage canals for an “osmotic city” designed for water management. However, Rostain has dismissed this theory as unfounded.
Anthropological questions also persist. Florencio Delgado, a professor at Universidad San Francisco de Quito, highlighted the absence of skeletal remains or burial grounds. “One of the most important questions for me is, where are the people?” he asked.
Data suggests the original mound-builders, the Upano, may have abandoned the site “briskly” around AD300 due to climate shifts, followed by Huapula people from AD600 until at least the 13th Century.
Conservation efforts
While the term “lost city” has gained media traction, experts like Kathryn Reese-Taylor of University of Calgary argue the term is inaccurate, as local communities and archaeologists have long been aware of the mounds.
Today, much of the valley is settled, and many tolitas are located on private farmland.
In Morona province, a volunteer group called the Guardians of Patrimonies – including data scientists and architects – works to report mound destruction and educate landowners.
In the town of Pablo Sexto, Mayor Yajaira Ramón Rodas has overseen the creation of a small archaeological park to celebrate the area’s heritage.
“The Amazon was not the end of civilisation,” Rostain remarked. “It was the cradle of civilisation”.
