The Atacama Giant is an anthropomorphic geoglyph on Cerro Unitas in the Atacama Desert, Chile. It is the largest prehistoric anthropomorphic figure in the world with a length of 119 metres (390 ft), and represented a deity for the local inhabitants from AD 1000 to 1400.
The figure was an early astronomical calendar for knowing where the moon would set; by knowing this the day, crop cycle, and season could be determined. The points on the top and side of the head would say what season it would be depending on their alignment with the moon, which was important in determining when the rainy season would come in the barren Atacama.
The Atacama Giant is one out of nearly 5,000 geoglyphs – ancient artwork that is drawn into the landscape – that have been discovered in the Atacama in the last three decades. It is believed that they are the work of several successive cultures that dwelt in this region of South America, including the Tiwanaku and Inca.
According to en.wikipedia