Peru Holds Oldest New World City.

New York City is the Big Apple. New Orleans is the Big Easy. Now, make way for Caral, an ancient Peruvian city that qualifies as the Big Mound.

Six huge, mound-shaped ceremonial platforms at Caral date from 4,000 years ago, an archaeological team reports in the April 27 SCIENCE. That makes the site, located in the Supe Valley about 14 miles from the Pacific Ocean, the oldest-known urban center in the Americas.

Moreover, preliminary evidence indicates that at least 2 of 17 other comparably sized archaeological sites in the Supe Valley flourished at the same time that Caral did, says Jonathan Haas of the Field Museum in Chicago.

Haas suspects that a network of ancient, inland metropolises, including Caral, traded extensively with coastal outposts. "Supe Valley cities were the big gorilla on the ancient South American landscape," he says. "Everyone else was mouse lemurs."

Caral's massive size and great antiquity demonstrate that large-scale South American civilizations need not have originated on the coast, as one influential theory holds, according to Haas and his colleagues Ruth S. Solis of Universidad Nacional Mayor de San Marcos in Lima, Peru, and Winifred Creamer of Northern Illinois University in De Kalb.

Although archaeologists discovered it in 1905, Caral had attracted little scientific attention until now. It lies in a remote area with no paved roads or basic amenities. Moreover, the site contains no pottery, since its residents didn't make ceramic vessels. This has discouraged both archaeologists and looters.

The site's central zone contains the six large mounds, many smaller platform mounds, two sunken circular plazas, and various residences and buildings. Platform mounds housed high-status citizens and served ceremonial functions.

For radiocarbon dating, the researchers focused mainly on reed fibers from woven bags they found at the site. Caral's workers used the bags to carry rocks for building the mounds, the researchers say. The reeds, which live for about 1 year, provide highly specific age estimates of when the workers built the platforms.

Construction occurred from about 4,090 to 3,640 years ago, the researchers say. Activity at the site may have begun as early as 4,700 years ago, Haas adds.

Remains at the site indicate that Caral's people grew crops such as beans and squash--but not corn--in irrigated fields. Seafood, probably acquired through trading, provided most of their protein.

For perhaps the first time in the New World, authoritarian leaders assumed power at Caral and forced their subjects to do the heavy labor needed for massive building projects, Haas proposes.

The political structure at Caral may not have been as authoritarian as Haas envisions, remarks archaeologist Daniel Sandweiss of the University of Maine in Orono. Still, he calls the new age estimates for Caral "very significant."

"Caral is a huge site considering how old it is," says archaeologist Betty J. Meggers of the Smithsonian Institution in Washington, D.C. "This is a revolutionary discovery."