The parched desert and hillsides made an inviting canvas: By simply removing a layer of dark stones cluttering the ground, exposing the lighter sand beneath, the Nasca created markings that have endured for centuries in the dry climate. Archaeologists believe both the construction and maintenance of the lines were communal activities—"like building a cathedral," says Reindel.
In the hyperarid southern valleys, early Nasca engineers may have also devised a more practical way of coping with the scarcity of water. An ingenious system of horizontal wells, tapping into the sloping water table as it descends from the Andean foothills, allowed settlements to bring subterranean water to the surface. Known as puquios, these irrigation systems still water the southern valleys.
Perhaps because of the adversity they faced, the Nasca people seem to have been remarkably "green." The creation of the puquios displayed a sophisticated sense of water conservation, since the underground aqueducts minimized evaporation. The farmers planted seeds by making a single hole in the ground rather than plowing, thus preserving the substructure of the soil. During a visit to a Nasca site called La Muña, Isla pointed out layers of vegetative matter in the walls of buildings and terraces that marked the rocky hillside settlement. The Nasca, he said, recycled their garbage as building material. "It's a society that managed its resources very well," he said. "This is what Nasca is all about."
To most people today, Nasca is all about the lines. But although the Nasca were certainly the most prolific makers of geoglyphs, they were not the first. On a hillside abutting a plateau south of Palpa sprawl three stylized human figures, with buggy eyes and bizarre rays of hair, that date to at least 2,400 years ago—earlier than almost any textbook date for the start of the Nasca civilization. Reindel's group has attributed no fewer than 75 groups of geoglyphs in the Palpa area to the earlier Paracas culture. These Paracas geoglyphs, which often depict stylized humanlike figures, in turn share distinct visual motifs with even earlier images carved in stone, known as petroglyphs. During a recent foot survey of a suspected Paracas site high in the Palpa River Valley, Isla came across a petroglyph of a monkey—a surprising, earlier incarnation of the famous Nasca geoglyph he had pointed out to me on the pampa below our plane.