From Wikipedia

Nazca Lines

The Nazca Lines are a series of geoglyphs located in the Nazca Desert, a high arid plateau that stretches more than 80 kilometres (50 mi) 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 metres (660 ft) 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.