The Nazca Lines include over 70 figures of animals and plants: a spider, a monkey with a coiled tail, a hummingbird, a condor, a whale, hands, and a tree. Some figures exceed 200 meters in length. The lines themselves - straight lines extending up to 50 kilometers - may number over 13,000.

The technique was simple: remove the reddish iron oxide pebbles that cover the desert surface to expose the lighter clay beneath. The desert's extreme dryness and lack of wind preserve the drawings - lines created 2,000 years ago look freshly made. The Nazca Pampa is one of the driest places on Earth.

The lines went largely unnoticed until commercial aircraft began flying over the region in the 1920s. Pilots reported strange patterns on the desert floor. Peruvian archaeologist Toribio Mejía Xesspe studied them from nearby hills in 1927, but their full extent only became clear from the air.

American historian Paul Kosok called them 'the largest astronomy book in the world' in 1941. German mathematician Maria Reiche devoted her life to studying and protecting the lines, mapping hundreds of figures and advocating for their preservation. She became known as the 'Lady of the Lines.'

Why create art visible only from the sky? Theories have ranged from the astronomical to the absurd. Some proposed the lines were landing strips for ancient aircraft or signals to aliens. More grounded theories suggest they were pilgrimage paths, ritual walking routes, or markers related to water sources.

Recent research suggests the lines may have pointed to water sources in the mountains or marked solstice alignments. Some may have been created for religious ceremonies - processional paths that worshippers walked while perhaps carrying offerings. The figures may have been meant for the gods to see from above.

The Nazca culture flourished from 100 BC to 800 AD in the coastal valleys of southern Peru. They were skilled agriculturalists who built underground aqueducts (puquios) still in use today. Their pottery and textiles show the same motifs found in the geoglyphs.

The lines required enormous coordinated labor but relatively simple technology. Stakes, cord, and the removal of surface rocks would suffice. The straight lines could be extended indefinitely using sighting poles. The curves of animal figures were likely planned on a smaller scale, then enlarged using a grid system. Engineering, not magic.

The Nazca Lines survived for two millennia but face modern threats. The Pan-American Highway cuts through the site. In 2014, Greenpeace activists damaged the site during a protest, leaving footprints near the hummingbird. In 2018, a truck driver deliberately drove across several lines.

UNESCO designated the lines a World Heritage Site in 1994. Drones and satellites now monitor for damage. Climate change may alter the desert conditions that preserved the lines. The ancient drawings that survived 2,000 years may not survive another century without active protection. The messages to the sky need guardians on the ground.