Ancient Andean Marketplace Mystery Solved: The Band of Holes Reveals Its Secrets
In a groundbreaking archaeological discovery, researchers have finally uncovered the purpose behind one of Peru’s most enigmatic monuments—a vast line of thousands of holes stretching 1.5 kilometers along the foothills of the Andes Mountains. Known as the “Band of Holes” or “Monte Sierpe” (serpent mountain), this remarkable earthwork has puzzled experts since its first aerial photographs appeared in National Geographic in 1933. According to findings published in the journal Antiquity on November 10, archaeologist Jacob Bongers from the University of Sydney and his colleagues have determined that this mysterious site served as a bustling regional marketplace for pre-Inca groups more than 600 years ago, before being repurposed by Inca rulers as a sophisticated tax collection center.
For decades, Monte Sierpe has inspired numerous theories about its purpose—ranging from defensive fortifications and water collection systems to gardening plots, ritual designs, or storage facilities. Some enthusiasts have even proposed fantastic claims of extraterrestrial involvement in its creation. However, the new research provides compelling evidence for a more practical yet culturally significant function. “Monte Sierpe looks like a snake, and its visual prominence was likely meant to attract trading partners,” explains Bongers. The serpentine appearance of the monument wasn’t merely aesthetic but served as a recognizable landmark for traders traversing the region. Economic exchanges both before and during Inca times likely incorporated important ritual elements that reflected shared beliefs among different groups, creating a space that was both commercial and culturally significant for participants.
The research team’s findings are based on meticulous examination of archaeological evidence from the site. Microscopic plant remains identified in 19 of Monte Sierpe’s holes revealed traces of crops such as maize and wild plants traditionally used in basket-making. Radiocarbon dating of burned wood found in one hole placed its use firmly within the 1300s, a time when the wealthy Chincha Kingdom controlled the region before the Inca conquest. Located strategically near the intersection of major pre-Hispanic roads and trade routes, Monte Sierpe provided an ideal location for groups from coastal plains and highland valleys to exchange goods. Bongers and his colleagues propose that Chincha-era traders likely lined the holes with plant fibers and placed various commodities like maize or other goods inside them, creating a physical system for displaying and organizing tradable items.
The remarkable structure of Monte Sierpe reveals sophisticated planning that facilitated large-scale economic activity. Using drone imagery, researchers discovered that the approximately 5,200 holes cluster into at least 60 distinct sections separated by empty spaces, with different sections displaying varying construction styles, such as holes with and without stone linings. The numerical patterns in the layout and quantity of holes across different sections correspond to patterns found on local Inca knotted strings called khipus, which officials used for record-keeping and accounting purposes. This correlation suggests that when Inca conquerors took over the Chincha Kingdom, they transformed Monte Sierpe from a marketplace based on bartering into a centralized tax collection facility where different community groups deposited tribute owed to Inca authorities according to their specific sections.
Like many recent archaeological discoveries throughout Central and South America, Monte Sierpe demonstrates the impressive organizational capacity of ancient communities to pool resources and labor for massive construction projects. This challenges earlier assumptions about the limitations of pre-Columbian societies and highlights their sophisticated systems of economic exchange and governance. University of Maine archaeologist Dan Sandweiss, while not involved in the research, notes that Bongers’ team makes a strong case for the Inca transformation of Monte Sierpe, though he cautions that “this explanation is likely but not absolutely proven.” Nonetheless, the multiple lines of evidence presented effectively counter pseudoscientific notions about alien involvement in the site’s creation.
The discovery offers a fascinating window into the economic and political transitions that occurred in the region as the Inca Empire expanded its influence. Bongers speculates that each segment of Monte Sierpe corresponded to a local kin or community group, with these groups taking turns maintaining the thousands of holes and depositing goods into their respective sections as part of the Inca tribute system. This arrangement would align with Inca tribute lists for Andean communities that were recorded by Spanish chroniclers in the 16th century. Whether used for trading or collecting tribute, Monte Sierpe stands as a remarkable testament to the ingenuity and organizational capabilities of pre-Columbian Andean societies, providing valuable insights into their economic systems and the ways in which powerful empires adapted existing infrastructure to serve new administrative purposes.
