The lines are shallow designs made in the ground by removing the ubiquitous reddish pebbles and uncovering the whitish ground beneath. Hundreds are simple lines or geometric shapes; more than seventy are designs of animal, bird, fish or human figures. The largest figures are over 200 metres (660 ft) across. Scholars differ in interpreting the purpose of the designs, but they 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 or giant astronomical calendars.
Due to the dry, windless and stable climate of the plateau and its isolation, for the most part the lines have been preserved. Extremely rare changes in weather may temporarily alter the general designs.