Scientists finally explain 5,200 mysterious holes in Southern Peru

5,200 mysterious holes in Southern Peru (Image: C. Stanish)

Archaeologists may have discovered the purpose of 5,200 holes. The holes are located on a ridge in southern Peru. They were carved into sediment and sometimes reinforced with stones. The site stretches about 1.5 kilometres and seven holes wide.

Who discovered the purpose? 

A team led by Jacob Bongers conducted recent fieldwork there. They mapped the holes and collected sediment samples from 1933. The samples contained starch, pollen, and plant remains from crops. Maize, amaranth, squash and cereals were all clearly identified.

Ancient marketplace or storage

Researchers believe the holes may have functioned as an early marketplace. People could place crops and goods into baskets for trade. Mobile farmers and fishers likely came to exchange their products. The holes may also have helped display items for visitors.

Inca repurposing

Later, the Inca appear to have reused the site systematically. The hole pattern resembles a Khipu, the knotted Inca accounting. Each block may have represented an account, tribute, or record. It could have functioned as a large-scale social accounting system.

Dates and Historical Context 

Radiocarbon dating suggests the earliest holes date before Inca arrival. Charcoal from one pit gave a date of 1320–1405 CE. The site therefore predates Inca expansion into the southern Andes. Later, the Inca repurposed the holes for tax and accounting.

Why this discovery matters?

The findings solve a long-standing archaeological mystery in Peru. They show how societies organised markets and recorded economic activity. The site illustrates sophisticated social technologies before and during Inca rule. Future research may clarify why this method was not widely replicated.