CARAL, Peru — A sudden wind gust blows eerily down from rocky Andean foothills, kicking up a cinnamon-colored cloud over the moonscape of ruins that is the oldest city in the Americas.

The sky is a crisp blue. All around in the Supe River Valley are lush fields of onion and corn.

We are in Caral, three hours and nearly 5,000 years from contemporary Lima, Peru's bustling capital, and we've spent the past half-hour or so on a bumpy drive from the coast, along a dirt road blocked periodically by bleating herds of goats and sheep.

Caral made headlines in 2001 when researchers carbon-dated material from the city back to 2627 B.C. It is a must-see for archaeology enthusiasts.

Even though the ruins in the dusty, wind-swept Supe River Valley don't approximate in majesty the mountains that surround the famed Inca ruins at Machu Picchu, they are an unforgettable sight under the glow of a fiery sunset.

Dotted with pyramid temples, sunken plazas, housing complexes and an amphitheater, Caral is one of 20 sites attributed to the ancient Caral-Supe culture that run almost linearly from Peru's central coast inland up the Andes.

The ruins changed history when researchers proved that a complex urban center in the Americas thrived as a contemporary to ancient Mesopotamia and Egypt — 1,500 years earlier than previously believed.

But much remains to be discovered about Caral and the Caral-Supe culture that flourished here for more than a thousand years.

Ruth Shady, a Peruvian archaeologist from San Marcos University, discovered Caral in 1994 and was stunned by its size and complexity.

"Caral combined size with construction volume, but also it was a planned city," she says.

Shady and her team continue working at Caral, but she also dedicates her time to promoting the project with Peru's National Culture Institute as a tourist and educational destination.

Caral received some 21,000 visitors in 2005, up from about 7,000 in 2003, the Commission for the Promotion of Peru says.

The ruins offer a front-row seat to archaeology in action, as scientists dust off piles of rock or supervise the reconstruction of a crumbling pyramid wall that thousands of years ago gleamed red, yellow or white.

The ancient society comes to life with the help of these archeologists, who make up about half of the site's tour guides along with locals whom they have trained.

The 163-acre city was the administrative center for a complex civilization.

While only crudely reconstructed, the society's clear class distinctions are evident in the wide variety of home sizes and neighborhoods.

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.