The misterious designs are shallow lines made in the ground by removing the reddish pebbles and uncovering the whitish/grayish ground beneath.Some people differ in interpreting the purpose of the designs but, in general, they ascribe religious significance to them.
The dry, windless, stable climate of the plateau its the reason why the lines have mostly been naturally preserved. Extremely rare changes in weather may temporarily alter the general designs. As of 2012, the lines are said to have been deteriorating because of an influx of squatters inhabiting the lands. something very sad.
Did you know?
Contrary to the popular belief that the lines and figures can only be seen from an aircraft, they are also visible from the surrounding foothills and other high places.
The first mention of the Nazca Lines in print was by Pedro Cieza de León in his book of 1553, where he mistook them for trail markers. Partially visible from the nearby hills, the first to distinguish them were Peruvian military and civilian pilots.
Forward to the year 1927 the Peruvian archaeologist Toribio Mejía Xesspe spotted them while he was hiking through the foothills. He discussed them at a conference in Lima in 1939.
Paul Kosok, a historian from Long Island University, is credited as the first scholar to seriously study the Nazca Lines. He flew over the lines and realized one was in the shape of a bird. Another chance helped him see how lines converged at the winter solstice in the Southern Hemisphere. He began to study how the lines might have been created, as well as to try to determine their purpose.
He was joined by Maria Reiche, a German mathematician and archaeologist , to help figure out the purpose of the Nazca Lines. They proposed one of the earliest reasons for the existence of the figures: to be markers on the horizon to show where the sun and other celestial bodies rose but archaeologists, historians, and mathematicians have all tried to determine the purpose of the lines untill this very day.
Determining how they were made has been easier than figuring why they were made. Some have theorized the Nazca people could have used simple tools and surveying equipment to construct the lines. Archaeological surveys have found wooden stakes in the ground at the end of some lines, which support this theory.
One such stake was carbon-dated and was the basis for establishing the age of the design complex. The Nazca “drew” several hundred simple but huge curvilinear animal and human figures. In total, the earthwork project is huge and complex: the area encompassing the lines is nearly 450 km 2 (170 sq mi), and the largest figures can span nearly 1,200 ft (370 m).  Some of the measurements for the figures conclude that the hummingbird is 93 m (310 ft) long, the condor is 134 m (440 ft), the monkey is 93 m (310 ft) by 58 m (190 ft), and the spider is 47 m (150 ft). The extremely dry, windless, and constant climate of the Nazca region has preserved the lines well. This desert is one of the driest on Earth and maintains a temperature around 25 °C all year round. The lack of wind has helped keep the lines uncovered and visible.
The discovery of two new small figures was announced in early 2011 by a Japanese team from Yamagata University. One of these resembles a human head and is dated to the early period of Nazca culture or earlier, and the other, undated, is an animal.
In March 2012, the university announced a new research center would be opened at the site in September 2012 to study the area for the next 15 years.
The team has been doing field work there since 2006 when it found about 100 new geoglyphs .
someday we will know the truth about the Nazca Lines?.