A Huge Lost City In The Amazon

The archaeological culture associated with this lost city, the same size as Roman era London, is so obscure that it didn't even have its own Wikipedia page and wasn't mentioned in the Pre-Columbian History of Ecuador page on Wikipedia.

LIDAR has discovered a city that was once home to 100,000 people in eastern Ecuador, in a time period roughly contemporaneous with the Roman Empire, that was ultimately reclaimed by the Amazon jungle. As Boing Boing explains:

Other reports describe it as a "valley of lost cities" spread throughout the region. The implications appear to be quite spectacular: a sprawling urban civilization larger than nearby Mayan cultures.

The linked report isn't quite as generous in estimating the number of people who lived there, but provides further details:

The settlements were occupied by the Upano people between about 500 BC and AD 300 to 600 – a period roughly contemporaneous with the Roman empire in Europe, the researchers found.

Residential and ceremonial buildings erected on more than 6,000 earthen mounds were surrounded by agricultural fields with drainage canals. The largest roads were 33 feet (10 meters) wide and stretched for 6-12 miles (10-20km).

While it is difficult to estimate populations, the site was home to at least 10,000 inhabitants – and perhaps as many as 15,000 or 30,000 at its peak, said archaeologist Antoine Dorison, a study co-author at the same French institute. That is comparable to the estimated population of Roman-era London, then Britain’s largest city.

The article and its abstract are as follows: 

A dense system of pre-Hispanic urban centers has been found in the Upano Valley of Amazonian Ecuador, in the eastern foothills of the Andes. Fieldwork and light detection and ranging (LIDAR) analysis have revealed an anthropized landscape with clusters of monumental platforms, plazas, and streets following a specific pattern intertwined with extensive agricultural drainages and terraces as well as wide straight roads running over great distances. Archaeological excavations date the occupation from around 500 BCE to between 300 and 600 CE. The most notable landscape feature is the complex road system extending over tens of kilometers, connecting the different urban centers, thus creating a regional-scale network. Such extensive early development in the Upper Amazon is comparable to similar Maya urban systems recently highlighted in Mexico and Guatemala.

Rostain, et al., "Two thousand years of garden urbanism in the Upper Amazon," Science (2024).

According to the Supplemental Materials:

Based on radiocarbon dating mentioned above and on the stylistic and stratigraphic classification of the remains discovered during our excavations, a cultural chronology of 2700 years could be established for the region. This sequence was recently revised and will be presented in a subsequent paper. It presents the succession of four or five cultural assemblages: 

1. Sangay culture: from around 700 to 500 BCE. This first occupation left few remains. 

2. Kilamope Culture: from 500 BCE. These were the first mound builders. Pottery of Kilamope culture is characterized by curvilinear incised decorations, the use of reddish slip and various fine prints and incisions.  

3. Upano Culture: probably from 500 BCE to 300/600 CE. They built earthen mounds and they were contemporaneous or successors of the Kilamope groups. Pottery of the Upano culture is mainly characterized by rectilinear incisions and painted decorations. 

4. Huapula Culture: from 800 to 1200 CE. After the disappearance of the Upano, Huapula groups reused the mounds abandoned by their predecessors. Huapula ceramic is characterized by decorations based on the corrugated modality using wavy patterns, and marks the appearance of modern Jivaroan-speaking populations in the region. 

5. Shuar Culture: They follow the Huapula of whom they are the direct heirs. The cultural evolution of this region is comparable with that known in other Amazonian areas: after sparse occupation, appearance of dense societies during the first phases (Kilamope and Upano cultures) while around 800 CE, the archaeological record indicates a fragmentation of the system with the emergence of smaller and dispersed groups. 

Since the European contact and until the end of the 19th century at least, the Upano basin has been occupied by Shuar groups of the Chicham-Aents culture (recent self-naming to replace the previous inadequate term “Jivaro”). Then came the Spaniards and, later, settlers coming from the Andean high plateaus.

The Supplemental Materials also mention and briefly describe four other ancient Amazonian urban centers that have been located in Cotoca, Llanos de Mojos, Bolivia; Hertenrits, Western coastal plain, Suriname; Kuhikugu, Upper Xingu, Brazil; and El Gaván, Llanos de Barinas, Venezuela.