The Nazca Lines are a vast field of designs scraped into the desert of southern Peru, so large that their forms are fully legible only from the air, which has made them both famous and misunderstood.
How they were made
The lines were created by the Nazca culture, and in part the earlier Paracas, mainly between about 500 BCE and 500 CE, by removing the dark oxidised stones of the desert surface to expose the pale ground beneath. Because this coastal desert is among the driest and stillest places on earth, the shallow marks have survived for two thousand years. They range from long straight lines and geometric figures, trapezoids and spirals, to biomorphic drawings of a hummingbird, monkey, spider, condor and other creatures, some hundreds of metres across.
What they were for
Their purpose is debated but the leading interpretations are religious rather than mysterious. Many lines appear to relate to water and fertility in a desert where water was the overriding concern: some point toward sources of water or mountain deities, and the figures may have been walked in procession as ritual pathways or offerings to deities who controlled rain and springs. An older idea that the lines formed an astronomical calendar has found little statistical support. The claim, popularised in the twentieth century, that they were made by or for extraterrestrials has no evidence and is rejected by archaeology; the Nazca had the technology and the motive to make them.
Preservation
The geoglyphs are extremely fragile, and modern threats, road-building, squatting, off-road vehicles and even careless demonstrations across them, have caused damage. They are a World Heritage site, and new figures continue to be found through aerial and satellite survey, extending the known extent of one of the largest ritual landscapes of the ancient Americas.