Right Angles only by Accident: An Essay on Inca Masonry

It took a recent trip to Peru–my first–to make me realize with curious shock that in the entirety of Arauco there is but one thing witnessed by Juan de Cardeña that today exists essentially unchanged … and that extraordinary thing is Inca masonry.  Scarcely troubled by earthquake, merely touched by the finger of time, such structures as the Spaniards did not disassemble or destroy still stand titanic, enigmatically offered to our admiration.  So, in my continuing effort to “illustrate” and “footnote”  Arauco, I here present (with explanation) some of the architecture and masonry my historical hero surely would have seen.

In the Inca heartland–no matter how humble–structures were invariably made of stone. And no mortar was ever used.  The one great variable was the quality of the masonry.  Some of the roughest (called “rubble masonry” by experts) can be found in the terraces that are a signature element of Inca agriculture.  Here is a perspective on Pisac, a site in the Sacred Valley, not far from Cusco:

Distance depicts the precision and beauty of these terraces, but gives absolutely no idea of their size.  Here a photo provides people for scale:

Pisac wallYou will note that the stones are in no way fashioned.  They are simply “stacked” (leaning slightly In) with such art that they have survived more than half a millenium.

Below are the terraces of Moray, another Inca site in the Sacred Valley:

Here a person (my wife) provides scale.  The masonry, as in the terraces at Pisac, is simply a precise stacking of stones.
Moray--Barb for scale

Remarkable as such Inca stone craft is, it attains a level of craftsmanship unmatched by any civilization in edifices erected for nobles and the sapa Inca himself.  In these, every stone is shaped to conform to those about it.  According to chroniclers, all of Cuzco–that city sacred to the Incas–was so constructed.

This is a typical section of a magnificent Cuzco wall which survived Spanish depredation.
Cuzco wall (1)

Here’s another part of that same wall, my wife providing scale.  The large stone she stands by is famous as having twelve “angles.”

Barb and wallEach huge ashlar is unique, shaped to fit those around it.  Amazingly, the Inca masons did not use metal tools to do this, but ground the stones in place, using yet harder stone and a slurry of sand and water.

The same sort of masonry construction was used in a much larger scale to build Sacsayhuaman, the temple/fortress which overlooks the city of Cuzco.  Since it was used as a kind of quarry by Spaniards from the time of the conquest (amazingly, I was told, until the 1970’s) a small fraction of the immense structure survives.  Not unsurprisingly, these are the very largest ashlars, which comprise the lowest part of the temple/fortress.  This Wikipedia photo depicts present Sacsayhuaman as a whole, Cuzco to the left, below:

A remarkable segment of a Sacsayhuaman wall:

And another segment with truly immense ashlars.  The largest stones used to construct Sacsayhuaman are thought to weigh between 128 and 200 tons.


Sacasayhuaman was (and is) extraordinary.  But the finest, most painstaking examples of Inca ashlar masonry were devoted to their sacred places, which were not always, not exactly, temples.  At Machu Picchu you can tell the sacred from the less so, simply by the masonry.  Consider the photo below….
Inca_temple (2)

At the bottom,the masons seem to have been given instructions as to quality which changed in the lower courses.  But above this secular confusion is the so called Temple of the Sun, distinguished both by that Inca rarity, a curved wall, and even more by the regular perfection of its masonry.

A view of that same “temple” from above (the Urubamba River below):
FW5A3512 - 2014-11-02 at 19-14-01

As your present guide I might point out that the sun, shining through the window built by the sacred rock enclosed by this “temple,”aligns its light with the carving on the rock at the winter solstice.

From this perspective you can get a better feeling for how Inca masons built their walls.  You will also notice that, like all Inca walls, this one slopes in.  This means that not only is every ashlar uniquely shaped to its place, but that (seen from the side) they are nothing like rectangles, and irregular even as parallelograms.  In Inca architecture there is nothing even remotely modular, like a brick.

Perhaps the finest Inca masonry left standing in Peru is what remains of Coricancha, the temple complex devoted to the sun (and a variety of other deities) in Cuzco.  The photo below shows, on the right, what remains of one exterior wall:

Much of Coricancha was destroyed, replaced by an immense (and immensely ugly) cathedral. But enough of the remarkable original remains to give one an idea of its masonry. The interior of one of the temples in the Coricancha complex now looks like this:


In its time and glory, the niches would have displayed Inca divinities fashioned from gold.  The stark, complex beauty of this room would have been covered by colorful tapestry of softest alpaca, this sacred space filled with a myriad precious things placed there by Incas to worship and honor their gods….

What the historical Juan de Cardeña (as well as my fictional version) would have seen would have been much like this photograph … an emptied and despoiled space, yet still timelessly wondrous in its beauty, the labor of its masons no a less a tribute to to the gods than the “idols” of the Inca goldsmiths, melted down by Spaniards to pay for their religious wars.