One complex thought to have housed farmers was partly excavated on the outskirts of Caral, on a dry and inhospitable patch of land, while a spacious home for wealthy families was built beside the important and impressive Huanca Pyramid, with its steep staircases that narrow as they reach the structure's flat top.

Caral's largest social class was dedicated to agricultural production, Shady says. Farmers, using irrigation canals, nourished their crops of pumpkin, squash, sweet potatoes, corn, chili peppers and cotton with the waters from the Supe River.

Musicians played flutes crafted from pelican and condor skeletons and horns made from llama or alpaca bones in the city's amphitheater.

Shady has also uncovered evidence of extensive trading. Shrimp and mollusks from Peru's coast have been found at Caral.

Caral-Supe residents capitalized on the various climate zones they inhabited by growing a wide variety of foods. The region's agriculture and fishing industries complemented each other.

"They managed an economy that articulated the productivity" of the various regions, Shady says.

Painstaking detective work and reconstruction is necessary, as these archeologists, little by little, uncover a lost world.

The Caral-Supe ruins are far from intact, unlike many of Peru's famed Inca ruins that date back half a millennium and are scattered throughout Peru's Sacred Valley in the Andean state of Cuzco.

Machu Picchu in nearby Cuzco is, of course, the country's top tourist destination.

Aspero, another major Caral-Supe site on Peru's central coast, 16 miles from Caral, was discovered in 1905, but its pyramids were thought to be naturally formed hills. A garbage dump was built on top of it, and as Shady's team excavates, trash needs to be cleared away.

They have discovered that fishermen from Aspero provided sardines, anchovies, and other fish for the sprawling culture.

"We're going to be able to learn about the social system, the economic and political organization, the ideology," Shady said of the excavations throughout the Supe Valley.

"It's very important, because it's the oldest civilization in America. And for that reason, native peoples see it as a symbol that in America there had been the same capacity to create civilizations as ancient as in the Old World," Shady said of the excavations throughout the Supe Valley.