Changing Planet

Threads That Speak: Unraveling the Mysteries of the Inca

The Inca Empire stretched from Colombia to central Chile and ruled more than 12 million people. They built organized cities and advanced road systems, yet they had no system of hieroglyphic writing, as the Maya did. Instead, they communicated via a system of knotted textile strings known as quipus. Deciphering how to read the quipus has become one of the great mysteries of ancient Peru.

At the site of Incahuasi in the Cañete Valley, archaeologists have found—for the first time—dozens of quipus buried alongside centuries-old produce. They appear to have been used for accounting in agricultural storage houses to record the amount of wood, beans, corn, chili peppers, and other items moving throughout the complex. Six-hundred-year-old beans are so well-preserved in this dry valley that they look like dried beans you would see in a market today. Archaeologists found beans and other produce so they knew they were excavating storerooms, and then they found knots.

Dr. Alejandro Chu and his team show the National Geographic crew where they are excavating. Photograph by Sarah Joseph
Dr. Alejandro Chu and his team show the National Geographic crew where they are excavating. Photograph by Sarah Joseph

National Geographic explorer Alejandro Chu explains that this is significant for quipu scholars because new discoveries could help bring them closer to understanding what the accounting records mean. “Usually you find quipus related to offerings, or funerary bundles in tombs. They are left and totally disconnected from their real use,” Chu says. “One of the main reasons why the discovery of quipus in Incahuasi is amazing is because it’s one of the first times we’re finding them in their original context. They are in the places where they were used.”

Conservator Patricia Landa explains the process of cleaning and preserving quipus. Photograph by Sarah Joseph
Conservator Patricia Landa explains the process of cleaning and preserving quipus. Photograph by Sarah Joseph

Quipus are made of a cotton or wool strings hanging from a main cord. The knots on the strings convey meaning through their location, direction, and type. Researchers already have a basic understanding of the numerical system incorporated in the quipus, where knots represent numbers. The hope is to move beyond mathematical operations to understanding non-numerical words or phrases from the agricultural product inventories. It is a whole new body of data to add to the Quipu Database Project and to understanding this interesting form of communication.

Incahuasi, or “House of the Inca,” is an important and strategic Inca city. It served as the agricultural base of operations and administrative center for the Inca expansion along southern coast in the late 15th and early 16th centuries. It transformed the valley into a thriving, productive area. In two archaeological excavation seasons led by Chu, the team has already found almost 70 quipus, and most of the vast storeroom complex at the site is yet to be excavated.

GlobalXplorer° is a cutting-edge platform that empowers citizen scientists around the world to help reduce looting and encroachment at important archaeological sites—as well as discover and protect unknown sites—using satellite imagery. Find out how you can become part of the GlobalXplorer° community and make a difference, beginning with our first expedition in Peru, at

Video Credits:
Senior Producer: Sarah Joseph
Producer: Carolyn Barnwell
Editor: Dave Nathan
Director of Photography: Juan Antonio Puyol
Executive Producer: Vanessa Serrao

Carolyn Barnwell has been a producer on the Science and Exploration Media team at National Geographic for over five years. She creates content to support the non-profit National Geographic Society including impact initiatives and the important work of explorers and grantees around the globe. She wrote, produced and edited for Nat Geo’s first-ever web series focused on explorers in the field: Expedition Raw and Best Job Ever. She loves yin yoga, wildlife encounters, and eating baked goods while they are still warm from the oven.

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