The Nazca Lines may have been giant pathways walked in ritual

Across the dry coastal plain of southern Peru, the Nazca culture (c. 200 BCE-600 CE) scraped enormous figures and lines into the desert. They made them with a remarkably simple method: removing the dark, oxidised surface stones to expose the lighter ground beneath. Because the region is so arid and windless, the designs have survived for two millennia.

The scale is staggering. The figures include a spider, a hummingbird, a monkey and a condor, some hundreds of feet across, alongside dead-straight lines running for kilometres.

Their purpose is debated. An early idea cast them as a giant astronomical calendar, but that view has lost ground. The more widely held theory today is that the lines were walked as part of religious rites and processions - many radiate from hills and water sources, suggesting ceremonies tied to water and fertility in a parched land. UNESCO inscribed them as a World Heritage Site in 1994.