Civilization in the Peaks of the Andes

By Joe Riley

The Inca Empire is generally regarded as the largest pre-Columbian civilization in the Americas, but from the 12th century AD until the early 1400s, the Inca people lived as a pastoral tribe in the area surrounding the city of Cusco. It was only after Sapa Inca (the title given to the Inca leader) Pachacuti came to power in 1438 AD that the Incan territory expanded from a small kingdom surrounding the capital at Cusco to a large empire stretching from what is now southern Colombia all the way to central Chile.

Besides expanding Incan territory and consolidating various different Andean tribes under one rule, Pachacuti is also well known for launching a building program that not only rebuilt much of the city of Cusco, but also created such famous sites as the Koricancha Sun Temple, Machu Picchu, and the Capac Ñan, the royal Incan highway system.

Mark Adams, in his book Turn Right at Machu Picchu explores the architecture of many of these Incan sites, in addition to ones built before and after Pachacuti’s reign, all while retracing the steps of Hiram Bingham III’s various Peruvian expeditions during the early 1900s.

One of the most interesting aspects of the Incan architecture that Adams observes is that most of the buildings are constructed without the use of mortar. Instead, the stones are so precisely cut and shaped and fit so closely together that a knife cannot pass between any two stones. And it is not only the buildings that are constructed in this manner, but also many of the stone walls and bridges along the Capac Ñan, the highway system that traversed the whole of the Incan Empire.

Despite generally not using mortar, Incan masonry was very stable. The walls of their buildings were slightly inclined toward the inside, giving the buildings great seismic resistance. In the case of an earthquake, the stone blocks would settle right where they belonged after only a bit of shifting during the tremor.

The Incans did all the carving of these stones with bronze, copper and stone tools. Unlike the civilizations of Europe and Asia, the Incan Empire (and much of the Americas) never went through an Iron Age, and so had no access to hard metals. Even so, the Incans were still able to create “one of the greatest imperial states in history,” in the words of Spanish conquistador Francisco Pizzaro, who conquered Peru in 1533.

Forging an empire as large the Incan’s without the use of iron tools is impressive enough, but the Incans also made do without the use of a writing system. They did have a spoken language, which was a form of Quechua, but there was no form of written communication. Instead, information was recorded through the use of khipus, which were groups of colored, spun or knotted cords decipherable only to a special class of khipu keepers. Because of this, no surviving khipus have been fully decrypted, although it has been theorized that the khipus use a system analogous to a computer’s binary code — very interesting to me as a computer science minor.

The Incans also had no real concept of the wheel. Transporting messages, goods and persons around the high peaks of the Andes was all done either on foot or through the use of alpacas and llamas. It is generally assumed that any advanced civilization needs to have invented the wheel at some point during their history, but in reality there’s only one civilization that invented it. Sometime around 3500 BC, an unknown Sumerian inventor came up with the concept of the wheel, and from there, it spread around Europe, North Africa and Asia. But the concept of the wheel never made it to the Americas due to that little bit of water separating it from the old world. In place of the wheel, the Incas made use of wooden rollers to transport heavy objects, although these were not attached to the object being transported, as a wheel would have been.

The majority of well-known ancient civilizations existed on fertile plains at low altitudes, but without the wheel, a writing system or hard metals, the Incans were able to build a vast and interconnected empire on the peaks of the second highest mountain range in the world, with some of the most impressive architecture of any ancient civilization. How they were able to do this still remains a mystery to many scholars, and with no written records from the Incans themselves, it will be a while until we are able to understand the Incans advanced ways.

An example of the khipus, used in the absence of a written records


Incan Masonry
A fine Example of Incan Masonry


Capac Ñan
The Capac Ñan going along a cliffside


Koricancha Sun Temple
Koricancha Sun Temple


Machu Picchu
Machu Picchu



3 Replies to “Civilization in the Peaks of the Andes”

  1. A writing system that uses a binary code is not something I’ve read about before. Are there other examples of writing systems that are based on a binary code?

    We’ll have opportunity to see Incan architecture and masonry after the conference in Lima.

    1. It’s not really a “writing system,” but the hexagrams that make up parts of the I Ching, an ancient Chinese manual of divination, represent the numbers 0 through 63 in a binary display. Other than this, I can find no other evidence of writing based on the binary numeral system. But the khipu is not a “writing system” per say, because there seems to be no correlation between the khipu and the Inca spoken language, Quechua. It is generally thought that the khipus were used only for record keeping, having no phonetic referent in the spoken language.

  2. Joe, very insightful! Although I did not read Turn Right at Machu Picchu this summer for my book of choice, I would love to read it before we leave for Peru. Like you mentioned, it is absolutely incredible how the architecture was built using tools and man power, rather than the machinery and technology available today.

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