According to Eitel and his University of Heidelberg colleague Bertil Mächtle, the microclimate in the Nasca region has oscillated dramatically over the past 5,000 years. When a high-pressure system over central South America called the Bolivian High moves to the north, more rain falls on the western slopes of the Andes. When the high shifts southward, precipitation decreases, and the rivers in the Nasca valleys run dry.
Despite the risky conditions, the Nasca flourished for eight centuries. Around 200 B.C., the Nasca people emerged out of a previous culture known as the Paracas, settling along the river valleys and cultivating crops such as cotton, beans, tubers, lucuma (a fruit), and a short-eared form of corn. Renowned for their distinctive pottery, they invented a new technique of mixing about a dozen different mineral pigments in a thin wash of clay so that colors could be baked into the pottery. A famous ceramic tableau known as the Tello plaque—showing several Nasca strolling while blowing their panpipes, surrounded by dancing dogs—has been viewed as an iconic snapshot of a peaceful people whose rituals embraced music, dance, and sacred walks.
The theocratic capital of early Nasca times was a sand-swept mecca called Cahuachi. The site, first excavated in the 1950s by Columbia University archaeologist William Duncan Strong, is a vast, 370-acre complex featuring an imposing adobe pyramid, several large temples, broad plazas and platforms, and an intricate network of connecting staircases and corridors. In their 2003 book on Nasca irrigation systems, archaeologist Katharina Schreiber of the University of California, Santa Barbara, and Josué Lancho Rojas, a local schoolmaster and historian, point out that the Nasca River, which goes underground about nine miles to the east, resurfaces like a spring on the doorstep of Cahuachi. "The emergence of water at this point," they write, "was almost certainly regarded as sacred in prehistoric times."
"Cahuachi was a ceremonial center," says Giuseppe Orefici, an Italian archaeologist who has led the excavation for many years. "People came here from the mountains and from the coast, bringing offerings." Among the artifacts unearthed were dozens of severed heads, typically with a braided rope strung through a hole drilled in the forehead, perhaps to allow the skull to be worn around the waist.
Elsewhere in the Nasca realm, people moved east or west along the river valleys as rainfall patterns shifted. The Peru-German archaeological initiative has explored the region from the Pacific coast to altitudes of nearly 15,000 feet in the Andean highlands. Almost everywhere they have looked they have found evidence of Nasca villages—"like pearls in the valley margins," says Reindel. "And near every settlement we find geoglyphs."