Ancient Peruvian Metropolis Predates Other Known Cities

National Geographic News
April 26, 2001
The ancient Peruvian site of Caral may have been one of the first urban centers in the Americas, thriving more than a thousand years before other known cities, according to a study in the April 27 issue of the international journal Science.

New radiocarbon dating analysis indicates that Caral's immense stone structures were built between 2600 and 2000 B.C. "This inland metropolis is therefore the same age as smaller maritime-based societies on the coast, previously thought to precede more complex societies," Science reported Thursday.

Archaeologists discovered Caral in 1905, but had not known its age until now.

It is one of 18 sites in the Supe valley of central Peru, all of which have monumental, or larger than house-size, architecture. Such structures are typically associated with civilizations younger than 1500 B.C.

"What we're learning from Caral is going to rewrite the way we think about the development of early Andean civilization," said Science co-author Jonathan Haas of the Field Museum in Chicago.

"Power Players"

Given the scale of architectural and agricultural development in Caral, Haas said, early urban planners were "power players."

"The size of a structure is really an indication of power," he said. "It means that leaders of the society were able to get their followers to do lots of work. People don't just say, 'Hey, let's build a great big monument.' They do it because they're told to and because the consequences of not doing so are significant."

Haas and his colleagues, Winifred Creamer of Northern Illinois University and Ruth Shady Solis of the Universidad Nacional Mayor de San Marcos in Lima, used radiocarbon dating to determine the age of reed fibers from shicra bags found at Caral. ("Shicra" is the indigenous word for "woven.")

According to the researchers, workers used the bags to carry rocks for building enormous structures called platform mounds, which were used for both ceremonies and as residences for high-status citizens. Instead of reusing the bags, workers placed them, rocks and all, inside the structures' retaining walls.

The Supe Valley stretches eastward from the Pacific coastline and up the slopes of the Andes. Caral has some of the largest buildings of all the sites discovered in the valley; the largest platform mound of Caral is approximately the length of two football fields, nearly as wide, and five stories high.

The site also has a variety of apartment-like buildings, whose residential nature was indicated by the trash found inside. Other buildings at the site may have been used for ceremonial or administrative purposes, according to Science. Some of the architecture at Caral, such as two sunken circular plazas at the center of the site, is also typical of many younger sites that have been discovered in South America.

Sophisticated Irrigation

Haas said the radiocarbon dating offers greater insight into the ancient settlement. "Certain structures at Caral are common in the Andes, but now we know that these are some of the first. It's like saying, 'We're looking at the first Christian church,' " Haas said.

Research indicates that Caral's inhabitants used irrigation to cultivate a variety of plants, but no grains. "The planning that irrigation requires and the large amount of labor needed to build the city both imply that Caral was a state with a powerful government," the scientists concluded.

How such a powerful irrigation structure arose in the first place raises interesting questions, Creamer said. Researchers have long assumed that most complex societies cultivated some type of grain, which can be stored in large amounts and exchanged for work.

"We assume that providing a surplus of food is one of the first ways of concentrating wealth," she said. "One of the really intriguing aspects of our research is that there wasn't a product like corn in the Supe valley, but they still managed to develop in this complex way."

Creamer speculates that the citizens of the Supe Valley cities may have used an alternative type of food "currency," such as dried fish. Although economic systems based on corn have been extremely common worldwide, dried fish may have worked well enough for the several hundred years before corn was available, she noted.

The scientists say more work is needed to solve this mystery and other questions about Caral and the other sites in the Supe Valley, such as whether they were inhabited at the same time.

In fact, most of the Supe Valley sites have yet to be studied thoroughly, according to Creamer. Part of the reason they have received little attention, she explained, is because the sites, when discovered, appeared to lack many of the typical artifacts sought by archeologists and museum curators. The area's remote location is also a factor. Even today, the valley has no paved roads, electricity, or a public water system.

The research on Caral was funded by the National Geographic Society, the Istituto Nacional del Cultura of Peru, the Universidad Nacional Mayor de San Marcos, the National Museum of Natural History, and Northern Illinois University.


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