The famous lines and animals carved into the Nazca Desert of Peru were made by hand in the simplest possible way: by systematically moving dark stones aside from the desired shape to reveal the lighter colored desert clay beneath. This process leaves the resulting figures, called geoglyphs, as a slight depression in the ground. Visibility is enhanced by the dark edges of the lines where the rocks are concentrated after removal (inset figures).
Lines were made over vast scales, some being as long as 9 mi (14 km). The animal outlines (biomorphs) are smaller, though still so large that they are best seen from the air. The humming bird is 886 ft (270 m) long and the spider about 164 ft (50 m) across. The geogyphs are registered as a UNESCO World Heritage Site and are strictly off limits to visitors, but some can be seen from a tower built especially to view them.
Geoglyphs were constructed by people of the Paracas and Nazca cultures. Modern dating suggests that the figures may have been built in stages over a period of time, perhaps between 200 BC and 700 AD. Composed of Cretaceous–Tertiary volcanics, the rocks were washed down from the Andes Mountains. Their relative darkness is partly the result of a coating of desert varnish formed over thousands of years. The underlying, hard pan, desert floor is tough and resistant to weathering. However, since the lines were first constructed, aeolian sediments have blanketed the area, somewhat altering the original color and contrast of the lines.
The picture at top shows archaeologist Katharina Schreiber inspecting the eye of a pelican. At right Schreiber and Renate Reiche are shown standing on one of the many long, straight lines. Renate and her sister Maria spent decades investigating, documenting and protecting the geoglyphs. – Dave Lynch