SACSAYHUAMÁN: Who Built Walls Meant to Be Seen from the Sky?

Sacsayhuamán is an imposing archaeological complex located on the hills overlooking the city of Cusco, Peru. It is best known for its enormous walls built with polygonal stone blocks—some weighing tens of metric tons—which were cut and fitted together with extraordinary precision.

The most recent part of the archaeological site is generally attributed to the Incas and was certainly used by them in the 15th century, likely for ceremonial, military, and symbolic purposes.

However, it is much more difficult to determine who built the oldest part of the fortress, located at the base. To understand just how great the difference is between the two structures, simply compare the two photos in this post. The upper part consists of blocks weighing several quintals. The lower part of the fortress consists of blocks weighing several dozen metric tons, perhaps even exceeding 100 metric tons.

All of this was built at an altitude of 3,700 meters. To give you an idea, Mont Blanc is 4,800 meters high.

According to archaeologists’ reconstructions, the builders of the upper part of the fortress had neither wheels nor pack animals. Yet it appears that the builders of the lower part of Sacsayhuamán transported stone blocks weighing up to 100 metric tons at that altitude. Humanly speaking, this should not be possible.

Even more intriguing is the shape of the lower section of Sacsayhuamán’s walls. When viewed from above, the arrangement of the walls forms the silhouette of a jaguar, an animal sacred to those peoples. But this shape is completely invisible from ground level. And there is no “highest point” from which to observe it. Those walls have that shape solely to be seen from the sky.

Only from the sky could one have verified whether the overall shape was correct. There are no alternatives.

It is said that when the Spanish “conquistadors” devastated the settlements in the area, they could do virtually nothing to those walls. They then claimed that they were not of human origin, but had been built by the Devil.

There is a stark contrast between the structures of known pre-Columbian civilizations and the walls of Sacsayhuamán. Known pre-Columbian civilizations simply did not possess the technological capability to build walls of such extraordinary scale and complexity, whose overall design can only be understood when viewed from thousands of meters above. But then, who built them?

A Different Possibility for Sacsayhuamán: Synthetic Stone?

Researchers from universities in Central and South America have recently taken up the challenge of analysing the enormous stones of Sacsayhuamán. And, incredibly, they concluded that some of these stones may be synthetic—in other words, geopolymers.

If this is correct, the builders would not necessarily have had to transport enormous stone blocks up the mountain. Instead, they could have transported the ingredients needed to manufacture the material directly on site, mixed them together, and produced the stone where it was required. The process of creating a geopolymer is entirely scientific and perfectly feasible—provided that you possess the necessary technology and knowledge of chemistry.

The Same Mystery in Egypt

In recent years, researchers have also proposed that the outer casing of Sneferu’s Bent Pyramid was not simply made from naturally quarried limestone, but from a form of synthetic stone, or geopolymer. Similar claims have also been made about some blocks of the Great Pyramid of Giza.

A geopolymer should not be confused with ordinary mortar or “Roman cement.” Once hardened, it can form a material with properties comparable to natural stone. If such techniques were really being used thousands of years ago, the implications would be extraordinary.

A Question That Remains

This leads to an unavoidable question. Modern geopolymer technology is extremely recent. So what kind of chemical knowledge would these ancient builders have needed to manufacture synthetic stone thousands of years before us?

And where did that knowledge come from?

Even more striking is the geographical problem. Why do we encounter similar questions on opposite sides of the Atlantic—in Peru and in North Africa? If ancient peoples in both regions really knew how to manufacture stone-like materials, then perhaps the technological history of the ancient world is far more complicated than we have been told.

All the evidence suggests that the lower section of Sacsayhuamán was not built by the Incas, but by an older population possessing far superior technological knowledge.

For those who wish to explore these topics further, the subject is discussed in detail in the following publications: