The Stonework of Calle Inca Roca

            One of the many spectacular sites that I visited during my recent trip to Cusco was Calle Inca Roca. Located just east of the Plaza de Armas, this pedestrian alley features the impressive megalithic stonework of Peru’s pre-Columbian (pre-European) time. For the tourist, this street also provides a unique bonus: the patterns of two of the Andes’ most spiritually symbolic animals are camouflaged within the stonework.

I discovered Calle Inca Roca by chance during my first morning in Cusco. Setting out early from my hotel, I ventured into the San Blas district, a beautiful and historic neighborhood popular for its artisan culture. I was on the hunt for breakfast, and my guidebook suggested Jack’s Café Bar for newly arrived tourists. (Their review was spot-on, by the way. Jack’s food is delicious, safe, and affordable – and the customer service is great.)

With a full belly, I set out for the Cathedral, retracing my footsteps west along Calle Hatunrumiyoc, or “Street of the Great Stone.” Along the way, I discovered the twelve angle-stone, which is probably the single most famous example of pre-Columbian stonework in Cusco. Clearly named for its remarkable shape, this boulder is emplaced in the street’s southern wall. On that day, it was crowded with tourists. So, I took several photos “from the hip,” and then decided to return early the next morning (which, by the way, is the best time to view Cusco’s sites).


Continuing along Calle Hatunrumiyoc, the seductive melody of flute music suddenly caught my ears, and I instinctively slowed my pace. Glancing to the left, I saw a narrow lane lit by the heavenly, golden glow of sunshine upon polished cobblestones. For a moment, I stood at the mouth of the alley, my eyes half-closed with the sun on my face, enjoying the soothing melody of wind pipes. But when I noticed the alley’s impressive stonework, my feet immediately carried me down a flight of steps to investigate.

            
Regardless how many times I see Peru’s “imperial” style of pre-Columbian masonry, each encounter leaves me more amazed. In terms of simplicity, beauty, and pure engineering genius, few architectural methods in the world can compete.

            
“Imperial” is actually a general term used to distinguish the methods found in important pre-Columbian religious and political buildings from the far more rustic styles that characterize common structures. Moreover, “imperial” refers a spectrum of designs. But for the sake of simplicity, this style can be divided into two sub-types:

·      Rectangular, “ashlar” blocks, laid in straight, horizontal rows (e.g., the Coricancha).

·      Polygonal stones, fit together tightly (e.g., Calle Inca Roca). Technically, the cyclopean styles of Sacsayhuaman, Ollantaytambo, and Machu Picchu are also polygonal styles of masonry.

The polygonal stones of Calle Inca Roca are fashioned from green diorite – an igneous rock whose composition is between that of granite and gabbro (in other locations, granite or limestone are used). Despite weighting several tons, the stones are fitted together with the precision of a jigsaw. Their joints are famously “tight” – a toothpick can’t even be inserted into them – and laid entirely without mortar. Each stone is individually shaped, polished, and its edges beveled. What’s more, the joints do not form 90-degree angles to the face of the wall (like the brick or cinderblock methods with which we are familiar). Instead, they “curve” into the wall, in a fashion similar to the cellular structure of plants. Many of the stones have inexplicable “knobs” or protrusions along their surfaces.

How did the masons quarry, move, shape, and set these massive blocks? After all, the pre-Columbian peoples of Peru are not known to have used the wheel. They did not have iron or steel. And they had no large work animals such as the horse or ox. So, how were these walls built? By whom? And why were different styles used?

These questions have yet to be soundly answered.

The most common explanation, however, is that the construction process involved hundreds of thousands of Inca laborers. As part of their annual tribute to the state, these men quarried stones, moved them on sleds or rollers, pushed and pulled them up earthen ramps, and pounded and grinded them into shape. Then the stones were set, reshaped, and reset until the fitting was perfect. The mysterious knobs or protrusions on the stones are theorized to have accommodated ropes or poles.

Perhaps most amazingly, the majority of imperial stonework throughout the Inca empire is alleged to have been built in less than 100 years. Not surprisingly, this version of history continues to be debated.

            
I soon discovered a sign on an easel outside an artisan’s shop. Evidently placed there for tourists like myself, it included a diagram of the adjacent stone wall. Two colorful overlays highlighted the shapes of animals formed by the stones. A jaguar was displayed above a serpent.

            
For the next half-hour, I walked up and down the wall, continually referring back to the sign, trying to identify the two animals. Without the sign, I never would have seen or guessed that these designs were even present. But eventually, I found both, and my already profound admiration for the builders of these walls grew.

            
According to the sign, the stonework along Calle Inca Roca was part of an “usnu,” or ceremonial platform. Evidently, this usnu was associated with the Palace of Inca Roca, the sixth Sapa Inca. Today, this building is overlain by post-Inca construction, an approach commonly taken in the years after the conquest. While many Spanish and modern structures have been devastated by earthquakes, the original pre-Columbian walls remain.

            
Over the next week, I continued to marvel at the pre-Columbian stonework of Peru. The imperial style, in particular, is as beautiful as it is architecturally sound. Famous variations can be found throughout the streets and buildings of Cusco, as well as individual sites like the Coricancha and Sacsayhuaman. It can also be seen at Ollantaytambo and Machu Picchu. The styles differ, allegedly by the purpose of the building and the availability of stone. But while convenient, these explanations are rather simple.

If you ask me, a lot of questions remain. Indeed, the mystery of pre-Columbian architecture is far from being solved.

Till next time, don't stop exploring!

Andrew C. Katen

©Andew C. Katen, 2017. Photos by Andrew C. Katen. Feel free to republish as long as credit is given.