Monte Sierpe, Peru
Source: https://archaeology.org/band
The Nazca Plateau is an extremely arid region, receiving only about 4 mm of precipitation per year and is home to the well-known Nazca Lines. This dry climate helps preserve many other formations, one of those things are a series of about 5,200 stone lined pits known as the Band of Holes or Monte Sierpe (serpent mountain) or Cerro Viruela (smallpox hill) that lies about 130 km south of the Nazca Lines. These holes are in a band that is about 14-22 m wide on a relatively north-south line for about 1.5 km and lie about 32 km from the Pacific along the Pisco River. These holes range in size from 1-2 m wide and 50-100 cm deep and have edges that are raised with the dirt removed to make the hole.
Source: https://archaeology.org/band
The exact purpose of these holes is still a mater of research, with early researchers thinking that they were empty or unused graves because they were structurally similar to graves found in other areas from when they were discovered in 1931 through the early 1970s when it was thought that they might have been used as storage as '[t]hey are between two important Inka [sic] sites (tambo Colorado and Lima la Vieja), and very near the point where the Inka coastal road crosses the road to the highlands'. In 2015, researchers used drones to map the structure as well as study of the structures themselves. They hypothesized that the holes were 'used to measure produce given to the inca state as tribute; the measurements might have been recorded on Incan khipus and reported to government officials'. About 120 km north, a storehouse with a grid on the floor that had 'produce such as peanuts, black beans, and chili peppers that had been preserved from some 600 years. Amid the foodstuffs were khipus, accounting devices the Inca used to track payments of tribute'. More recent research points to this site being older than the Inca Empire. The researchers think that 'the rulers of this kingdom designed the Band of Holes to serve a purpose that was vital to their success and that the Inca later expropriated it for use as a tribute depot'.
Source: https://archaeology.org/band
Part of what makes understanding this site's purpose so complicated is that there are very few artifacts in the area. Some potsherds have been found at the site that were dated to about 1000-1400 CE when the Chincha kingdom ruled the area, as do potsherds from a 'defensive settlement located around half a mile east [about 1 km] of the Band of Holes', with radiocarbon dates from about 1305-1410. This gives a period when they were used, but it doesn't give a duration that the holes were in use or how long they took to build. Researchers examined soil 19 of the holes for pollen or other botanical remains. They found a 'significant amount of pollen even at the most elevated parts of the site, distant from the agricultural fields, suggests that it was not transported by insects or the wind'.
Source: https://archaeology.org/band
The Chincha likely numbered more than 100,000, 'based on colonial reports that there were 30,000 male heads of household in its former territory paying tribute to the Inca when Spain conquered the area'. They were merchants, fishers, farmers, and craftspeople who harvested guano from an island about 16 km offshore that was used as a potent fertilizer. The holes are in a 'tranzitional zone between the costal plain and the highlands known as the chaupiyunga, the sort of area where people are known to have met and exchange goods', as well as being located on a trade route. One researcher stated that 'Monte Sierpe is in the perfect spot for a barter market place…[y]ou can imagine big festivals with people in multicolored clothing coming from all around to trade'.
The researcher think that the Inca began to push into the area during the 15th century, stating that '[a]s a big empire, the Inca didn't like marketplaces…They see something like this and think, "We don't want these people to be exchanging resources among themselves. We want the resources. Let's appropriate this and turn it into an accounting device"'.
