The Nazca Lines are a series of geoglyphs located in the Nazca Desert, a high arid plateau that stretches more than 80 km (50 miles) between the towns of Nazca and Palpa on the Pampas de Jumana in Peru. Although some local geoglyphs resemble Paracas motifs, these are largely believed to have been created by the Nazca culture between 200 BCE and 700 CE. There are hundreds of individual figures, ranging in complexity from simple lines to stylized hummingbirds, spiders, monkeys, fish, sharks or orcas, llamas, and lizards.
The lines are shallow designs in the ground where the reddish pebbles that cover the surrounding landscape have been removed, revealing the whitish earth underneath. Hundreds are simple lines or geometric shapes, and more than seventy are natural or human figures. The largest are over 200 m across. Scholars differ in interpreting what the lines were for but generally ascribe religious significance to them. "The geometric ones could indicate the flow of water or be connected to rituals to summon water. The spiders, birds, and plants could be fertility symbols. Other possible explanations include: irrigation schemes, giant astronomical calendars, or landing for spaceships."
The dry, windless, stable climate of the plateau has preserved the lines to this day, for the most part. Extremely rare changes in weather may temporarily alter the general designs.
One theory of the purpose of the lines is that the Nazca people's motivations were religious and that the images were constructed so that gods in the sky could see them. Kosok and Reiche advanced one of the earliest reasons given for the Nazca Lines: that they were intended to point to the places on the distant horizon where the sun and other celestial bodies rose or set. This hypothesis was evaluated by two different experts in archaeoastronomy, Gerald Hawkins and Anthony Aveni, and they both concluded that there was insufficient evidence to support an astronomical explanation.
In 1985, the archaeologist Johan Reinhard published archaeological, ethnographic, and historical data demonstrating that worship of mountains and other water sources played a dominant role in Nazca religion and economy from ancient to recent times. He presented the theory that the lines and figures can be explained as part of religious practices involving the worship of deities associated with the availability of water and thus the fertility of crops. The lines were interpreted as being primarily used as sacred paths leading to places where these deities could be worshiped, and the figures as symbolically representing animals and objects meant to invoke their aid. However, the precise meanings of many of the individual geoglyphs remain unsolved as of 2009.
Henri Stierlin, in his 1983 book , linked the Nazca Lines to the ancient textiles found wrapping mummies of the Paracas culture. The lines and trapezes may have been used as giant, primitive looms allowing for the fabrication of the extremely long strings and wide pieces of textile that are typical of the area. In this theory, the figurative patterns (smaller and less common) have only ritualistic purposes.
Some, such as Jim Woodmann, have proposed that the Nazca Lines presuppose some form of manned flight in order to see the figures properly and that a hot air balloon was the only possible available technology. Woodmann actually made a hot air balloon using materials and techniques that he believed would have been available to people at the time, in order to test this hypothesis. The balloon flew, after a fashion, but there is no evidence in support of Nazca-era hot air balloons,  and Woodman's work has been rebutted.