They are part of a system of aqueducts of the same type called puquios that were built by the pre-Inca civilization of Nazca about 1,500 years ago. The holes in the ground are designed to allow wind to blow into a series of underground canals, in which water from underground aquifers flows. The canals take the water to where it is needed. (Source?)
The aqueducts ensured the supply of water to the city of Nazca and the surrounding fields, allowing the cultivation of cotton, beans, potatoes, and other crops in an arid region.
