Puquios (from Quechua pukyu meaning source, spring, or water well) are ancient systems of subterranean aqueducts which allow water to be transported over long distances in hot dry climates without loss of much of the water to evaporation. Puquios are found in the coastal deserts of southern Peru, especially in the Nazca region, and northern Chile. Forty-three puquios in the Nazca region were still in use in the early 21st century and relied upon to bring fresh water for irrigation and domestic use into desert settlements. The origin and dating of the Nazca puquios is disputed, although some archaeologists have estimated that their construction began about 500 CE by indigenous people of the Nazca culture.

The technology of the puquios is similar to that of the Qanats of Iran and other desert areas of Asia and Europe, including Spain. A few puquios in northern Chile and in other parts of Peru were probably constructed at the initiative of the Spanish after the conquest of the Inca Empire in the 16th century.

The puquios first became a subject of study in the early 20th century. Although they had been known before, historic evidence was scarce. Around 1900 scholars noted that puquios, locally known as socavones (lit. shafts), were spread through the oases of Atacama Desert. In the 21st century, puquios, in various states of use and decay, still exist in the valleys of Azapa and Sibaya and the oases of La Calera, Pica-Matilla and Puquio de Núñez. In 1918 geologist Juan Brüggen mentioned the existence of 23 socavones (shafts) in the Pica oasis, yet these have since been abandoned due to economic and social changes. The puquios of Pica-Matilla and Puquio Núñez tap the Pica Aquifer.

The puquios of the Nazca (or Nasca) region are of most interest to archaeologists as the area was the center of pre-Columbian civilizations such as Nazca culture which flourished from 100 BCE to 800 CE. Most archaeologists believe that the Nazca puquios are of pre-Columbian origin, but some believe that they were built by the indigenous subjects of the Spanish colonists in the 16th century. The theory of a Spanish origin holds that the puquios technology is not substantially different from Spanish techniques used from the early conquest to drain mines. An early example is the mine of Potosí that was drained by subterranean canals as early as 1556 following instructions of Florentine engineer Nicolás de Benito. Another argument for the Hispanic origin of puquios is that a Spanish law in Peru decreed that water from pre-Hispanic waterworks must be shared among landowners while the water from Hispanic waterworks could be owned by a single landowner. In an 18th-century legal case, a judge ruled in favor of the Hispanic origin of the puquios in the Chancay valley.

Proponents for the pre-Hispanic origin of the Nazca puquios cite the establishment of large settlements in river valleys with puquios in the 6th century CE, an indication that the settlement was stimulated by the water supplied by the puquios. They interpret Nazca culture iconography as portraying puquios symbolically. Climatic change may also have been a factor as the region entered several centuries of extreme aridity after about 400 CE which required the construction of irrigation works, presumably puquios, to provide water for domestic use and irrigation. The first known historical writing to refer to puquios in Nazca was in 1605 by the Spanish cleric Reginaldo de Lizárraga. Lizárraga mentions that the "indios" (indigenous peoples) of the region made use of the puquios but does not specifically attribute their construction to either the Spanish or the indigenous people. He also mentioned the much-diminished population of the indigenous people, their numbers a fraction of their pre-Columbian population due mostly to epidemics of European diseases.

In the early 21st century Rosa Lasaponara, Nicola Masini, and their team of the Italian CNR (National Research Council), in cooperation with archaeologist Giuseppe Orefici, studied the Nazca puquios using satellite imaging. They found evidence that the puquios system was once much more extensive. Scholars were able to see how the "puquios were distributed across the Nazca region, and where they ran in relation to nearby settlements – which are easier to date." Satellite imagery also revealed additional, previously unknown puquios in the Nazca drainage basin. The team that conducted this study concluded that the puquios are pre-Hispanic. In addition, RPAS (Remotely Piloted Aircraft Systems), or drones, were used in 2016 to map and document five sample aqueduct systems in the Nazca region.

A scientific method to precisely date the puquios has not been found, but, despite doubts, the "general consensus in 2017 was that the Nazca puquios were of "pre-Hispanic, Middle Nasca [c. 500 CE] origin...with subsequent Spanish and Republican modifications." The pre-Columbian origin of the Nazca puquios does not contradict the likelihood that the origin of other puquios scattered sparsely around the Central and Southern Andes is Spanish.

The technology of the puquios is similar to that of the qanats of Iran and Makhmur, Iraq, and other ancient filtration galleries known in numerous societies in the Old World and China, which appear to have been developed independently. They are a sophisticated way to provide water from underground aquifers in arid regions.