Experts Uncovered A Giant 2,300-Year-Old Structure In The Desert — And It’s Causing Quite A Stir

It’s even more mind-blowing when you consider that the Chankillo complex was constructed roughly 2,300 years ago. And the incredible stone towers have been visible to modern-day people since at least the 19th century. Yet it took a 21st-century study to finally figure out their actual purpose.

“It seems extraordinary that nobody really recognized [the towers] for what they were for so long,” Professor Clive Ruggles from the University of Leicester told the BBC in 2007. The timespan is particularly intriguing considering just how impressive the site is. “I was gobsmacked when I saw them for the first time,” admitted Professor Ruggles. And he wouldn’t have been alone.

The Chankillo complex is found in the desert of the Casma Valley on the coast of Peru. To give you a sense of its extraordinary size, it occupies a massive 1.5 square miles of land — that’s about 726 football fields. And its 13 towers which have proven so perplexing are of considerable bulk too.

The structures are placed on the crest of a small hill in Chankillo. They are all rectangular and stand between 6 and 20 feet tall. And even though they’re thousands of years old, the towers are still in pretty good shape. But it’s the way the structures are arranged and accessed that makes them so interesting.

If you look carefully, you’ll see that the towers are organized from north to south across the ridge. There are evenly spaced gaps between each tower, too. This creates a striking serrated view that offers a clue to the site’s previously unknown purpose. The towers hide an easy way for people to scale to the tops of each edifice as well.

Yep, each tower has two staircases carved into them. You could walk these steps to the top of the towers, and you’d probably enjoy a mighty fine view if you did. But giving people a better look at the horizon is not the reason the towers exist. All the same, even esteemed experts were pretty slow in figuring that out.

As we mentioned, Chankillo first came to people’s attention in the 1800s. And in the time since, there have been plenty of theories about why the site was there. The prevailing thoughts were that the complex had been a place for ritual battles or fighting. There was an abundance of circumstantial evidence to support this, too.

First off, the site consists of three buildings. These buildings are each surrounded by walls that stretch up to 20 feet high. So while archaeologists might not have known why the buildings were constructed, the layout of the area gave off strong fortress vibes. And it wasn’t just those ringed walls that did it.

Think about it. You’ve got large, solid walls surrounding three buildings. There are stone towers to one side. The site is also positioned on a ridge above the landscape. All of these things combined would make Chankillo pretty easy to defend against potential attacks. And at the time the towers were built, repelling enemies could have been a big consideration.

That time — roughly 400 B.C. — is known as the Early Horizon period. And there are multiple areas around Chankillo that prove that contemporary people did in fact build impressive fortifications. It goes to show just how rife with conflict this part of Peru was during the era. But something about Chankillo just didn’t add up...

The thing confusing archaeologists was that Chankillo couldn’t have operated as a normal fort — if it was a fort at all. A cursory glance at its three buildings revealed to the experts that they would be easily penetrable by invading forces. Their solid construction evidently had some serious flaws.

Remember the three high walls surrounding the buildings? Those structures actually had multiple entrances. The first one had five places through which to come and go, the second wall had four entrances, and the final one had three. That’s hardly ideal if your ultimate goal is to keep people out of the buildings!

So perhaps the idea of Chankillo being some kind of impenetrable fortress was a little far-fetched. And maybe that’s why the experts came up with a new theory about the purpose of this complex. The first spark of the next idea seemingly came about when people realized that the buildings had been maintained surprisingly well.

It seems that this didn’t occur to anybody until the turn of the 21st century, though. Up until that point, no one had really bothered to give Chankillo a thorough investigation. That all changed in 2001 when finally someone decided to take a closer look. But what did it mean that the insides of the structures were strikingly clean?

The experts thought that this aligned with what they’d seen in other structures that had been built by cults. This led archaeologists to believe that Chankillo actually had a temple at its heart. It also meant that there had been some kind of ritualistic behavior happening on site. The problem was, nobody knew what this “cult” had been worshipping.

In 2013 Professor Brian Cox visited Chankillo for his BBC show Wonders of the Universe. The physicist described the people who built Chankillo 2,300 years ago as “a civilization we know almost nothing about.” But if researchers know very little about a group of people, how could they figure out why they built these buildings?

“The details of this culture and all traces of its language are lost,” Professor Cox continued. So anybody who’d been trying to research Chankillo had nothing but the buildings and structures themselves to interpret. There was simply no way of telling who’d built them. Luckily, though, the buildings did offer some clues.

“Its walls were once brilliant white and covered with painted figures,” according to Professor Cox. The experts could tell this, Cox said, even though “all but the smallest fragments of decorations are gone.” All the same, what had been left behind — combined with other details around the site — gave experts all the evidence they needed to get to the truth.  

“If you stand in the right place, you can still experience the true purpose of Chankillo, just as you could the day it was built,” Professor Cox said in Wonders of the Universe. But of course, he could state this confidently in 2013 — because two other experts had already published their definitive findings about the complex.

Dr. Ivan Ghezzi and Professor Ruggles were the men behind the report, which was published in the journal Science in 2007. Dr. Ghezzi had been studying for his doctorate in anthropology at Yale at the time of his discovery. Yet he had only been at Chankillo because he’d been studying fortresses. That’s when he thought something didn’t make sense.

Dr. Ghezzi’s initial study actually took place back in 2001. Before this, you’ll remember, people generally thought Chankillo had been a fort. Yet no one had so far come up with a satisfying explanation for the existence of the 13 towers. That all changed after the postgrad student began working at the site.

“Since the 19th century there was speculation that the 13-tower array could be solar or lunar demarcation — but no one followed up on it,” Dr. Ghezzi told student newspaper Yale News in 2007. The researcher spotted an opportunity, and he had the support of those around him. “So we said, ‘Let’s study it while we are here!’” the academic explained.

It didn’t take long for Dr. Ghezzi’s instincts to turn up surprising results. “In the first hours of measurements, we realized the nature and importance of the towers,” the academic told The New York Times newspaper in 2007. And while it would take six more years to get the final paper fit to publish, Dr. Ghezzi was positive of what he’d found.

Dr. Ghezzi focused his attention on two points found within those sturdy walls and buildings we mentioned earlier. These points are about 750 feet away from the 13 towers and situated to their east and west. And after the researcher took his first measurements, it became clear that these were observation areas of great importance.

But what had the ancient civilization who lived here been observing? According to Dr. Ghezzi’s research, the positions of the 13 towers aligned almost perfectly with where the Sun would rise and set over the course of a year. That couldn’t be a coincidence and it convinced the academic that the towers were there to observe the passing of the seasons.

Here’s how it works. Let’s imagine you’re standing on the observation point to the towers’ west side. And as you stand there, first thing in the morning, the Sun begins to rise above the horizon. Now all you have to do is make a note of where the Sun pops up in relation to the towers. Easy, right?

Well, easy and kind of ingenious. Because the position of the Sun as seen from the observation point will then tell you what time of year it is. There were no smartphones in 400 B.C., remember. So if the Sun appeared at the furthest right-hand point of the towers, that would mean it’s the summer solstice in Peru.

And if the Sun popped up at the opposite end of the towers, then you’d know it was the winter solstice. For the rest of the year, too, the Sun would rise at various points along the towers. So the 13 towers are, effectively, one big calendar. This revelation was groundbreaking for a number of reasons.

It meant that the Chankillo solar observatory was the earliest example of this kind of structure we’ve ever found. And not only that, but it’s also different from other solar observatories because it could tell the time throughout an entire year. “Archaeological research in Peru is constantly pushing back the origins of civilization in the Americas,” Dr. Ghezzi told Yale News.

Dr. Ghezzi also revealed that Chankillo is older than observatories found in Europe by about 1,800 years. It’s also roughly 500 years older than any similar building made by the Mayans. So while the experts may have known about similar ways our ancestors kept time, they had no idea just how long ago it had all started. 

Why did people do this? Well, it would’ve definitely helped civilizations to know when to plant various seeds and crops throughout the year. And it would allow them to pinpoint when exactly to honor any religious festivals that align with the seasons. But the researchers also realized that it could have had another purpose.

The experts knew about the Inca king who explicitly used the Sun to help make political decisions. He did this, apparently, because he thought of the Sun as a deity — and himself as a direct descendant of it. And considering the Incan Empire came much, much later than the Chankillo observatory, this could shed new light on the earlier complex.

Dr. Ghezzi and Professor Ruggles believe that the 13 towers could have been a pointed message to those who lived in the area. Basically, whoever owned or operated the towers was in charge of everybody else. So perhaps it was almost like they were saying, “I control the Sun!” At the time, that would have been an intimidating show of power.

And today, the site holds the same power as it once did. Even a seasoned researcher such as Professor Ruggles was won over by Chankillo’s impressive stature. “I am used to being disappointed when visiting places people claim to be ancient astronomical observatories,” the scientist told Yale News. But Chankillo was an altogether different story.

“Chankillo is one of the most exciting archaeoastronomical sites I have come across,” Professor Ruggles continued. He also found it hard to believe that the solar observatory had not been discovered many years before. But now we know what the structure is, we can begin to decipher insights into the lives of these long-lost people.

Professor Ruggles explained to the BBC that the size of the observation points raises an interesting issue. The expert said the point to the west of the towers could not have been very big. At most, he thought, only three people could have watched the sunrise from here at any one time. And this tells us something very important.

“All the evidence suggests that there was a formal or ceremonial approach to that point and that there were special rituals going on there,” Professor Ruggles said. So that means that not just anybody could have wandered up to the observation point and noted the time of the year. That job would probably have been left to someone very powerful in the civilization.

Professor Ruggles told the BBC that it was likely a priest “who watched the Sun rise or set, while in the plaza next door the crowds were feasting.” So even though the ceremonial crowds could’ve seen the Sun, they wouldn’t have witnessed it rise from that all-important vantage point. And access to that special spot was the true expression of ancient power.

And, as we said, you can still experience some of that power today. After all, the Sun rises and sets in pretty much the same way today as it did 2,300 years ago. So if you ever find yourself in the deserts of Peru without your Apple Watch, you’ll know exactly how to tell what time of year it is! Meanwhile, another Peruvian site has come under scrutiny — one that is more well-known, but still harboring many secrets.

Set at almost 8,000 feet above sea level, Machu Picchu remained hidden for centuries before being rediscovered by the Western world. And even though it’s now a major tourist attraction, there is much about the grand city that we still don’t understand. All the while, though, experts have been attempting to unearth Machu Picchu’s secrets – and they’ve had some very surprising results.

One such specialist is geologist Rualdo Menegat, who has been studying Machu Picchu for years in a bid to unravel the mystery of its construction. At times, then, he conducted field work at dizzyingly high altitudes, taking measurements from the ancient city itself. On other occasions, however, he pored over data in a laboratory thousands of miles away from the Andean peaks.

Finally, in September 2019, Menegat was ready to reveal the fruits of his labor to his peers. So, at an annual gathering of geologists, he outlined his theories about how Machu Picchu had been built – and why. And now these remarkable findings are inspiring others to look at the Inca Empire in a whole new light.

The story of the Incas began back in the 12th century at a small hamlet nestled in the Andes Mountains. There, a tribe of farmers lived and worked in the region known as Cusco, which lies roughly 11,000 feet above sea level. And, ultimately, these agriculturalists would band together to create their own city-state.

Then, in 1438, the leader known as Pachacutec Inca Yupanqui came to power. And under his direction, the Kingdom of Cusco began a ruthless expansion into the surrounding area. Historians believe, in fact, that in just a few generations the Incan Empire grew to incorporate much of what is now South America.

At its peak, the Inca civilization spanned 2,500 miles across vast swathes of Ecuador, Argentina, Bolivia, Colombia and Chile. And while Cusco remained the empire’s most important city, other grand settlements began springing up across the region. Then, in around 1450 or so, work began on another outpost that was located around 50 miles northwest of the Incas’ capital.

According to archaeologists, this new city, dubbed Machu Picchu, was conceived as a compound for Pachacutec and his inner circle. And the estate not only featured a lavish palace complete with its own toilet facilities and garden, but it was also equipped with multiple temples and other structures. In fact, approximately 750 people are thought to have lived in the city at its peak.

After Pachacutec died, his son Túpac took over, and Machu Picchu continued to thrive and grow. Change was coming, though, and the glory days of this city in the mountains were not to last. In 1526, you see, the Spanish conquistador Francisco Pizarro and his men arrived on the fringes of the Inca Empire.

Spurred on by dreams of great riches, the conquistadors pushed deeper and deeper into the empire with each passing year. In the meantime, the Incas themselves descended into civil war. And with its people weakened by turmoil and European diseases, this mighty civilization ultimately fell, with cities such as Machu Picchu left abandoned as a consequence.

Then, for almost 400 years, Machu Picchu remained half-forgotten in the mountains – its existence known only to a handful of local tribes. In 1911, however, the American adventurer Hiram Bingham arrived in the region now known as Peru. Apparently, he was originally searching for Vilcabamba – a fabled lost city that is believed to be the last refuge of the Incas.

While Bingham was in Peru, moreover, a local man guided him to the overgrown ruins of Machu Picchu – which the American initially believed to be the mysterious Vilcabamba. And even though this wasn’t quite the case, Machu Picchu was nevertheless launched to international fame. From that moment on, tourists eager to see the relics of a lost civilization began to trickle in.

Today, Machu Picchu is considered Peru’s top tourist destination, attracting almost 1.5 million visitors a year. And although some of these sightseers make the lengthy hike in from Cusco, many arrive via rail at the city’s purpose-built station. There is also talk of constructing an airport at the site – a plan that would change the face of the ruins for good.

But while the future of Machu Picchu looks uncertain, there are many who are still attempting to unravel its past. And despite the estate’s popularity with tourists, the Inca mountain city has done an impressive job at keeping its secrets over the years – with the construction of the remote citadel perhaps being one of the most enduring mysteries.

Today, it’s believed that the Incas used a dry-stone technique to build the city’s remarkable stone walls. Essentially, this means that the rocks were cut and fitted together without utilizing mortar. But how did these ancient people carry out such a detailed and challenging feat? And why did they choose to do it in such an isolated spot?

Well, Menegat – a researcher at Brazil’s Federal University of Rio Grande do Sul – sought to answer those questions. He noted, too, that the Incas appeared to have made a habit of constructing their cities in isolated and inaccessible locations. And as a geologist, he believed that the reason for this choice may lie somewhere below the ground.

“It seemed to me that no civilization could be established in the Andes without knowing the rocks and mountains of the region,” Menegat explained to Newsweek in September 2019. “It could not be built on a whim. It is part of a practice of building settlements in high rocky places. But what guides this practice? What knowledge of the rocks and mountains did builders need to know to succeed in building cities under these conditions?”

According to Menegat, this area had also not been explored by any previous research, leading him to set out to conduct his own study of the geology surrounding Machu Picchu. Using a combination of satellite photos and measurements taken at the site, he began to map the tectonic faults that crisscross the region.

Long before the Incas and Machu Picchu emerged, though, the Andes Mountains had been created by a great geological upheaval. Millions of years ago, the two sections of Earth’s crust known as the Nazca Plate and the South American Plate collided. And as the Nazca Plate was pushed beneath the South American Plate, a high ridge of rock formed.

In an attempt to understand the landscape surrounding Machu Picchu, then, Menegat conducted four separate field trips to the region. When he wasn’t up in the mountains, meanwhile, he pored over data in his university laboratory. And along with satellite imagery, Menegat used previous geological studies of the area to inform his research.

What’s more, Menegat was impressively thorough with his work. “At each stage of the research, I presented the results to Peruvian researchers from various fields of knowledge – geology, archeology, anthropology, architecture, urbanism, landscape ecology, and epistemology – and regions of Peru, so as to assure me of the correctness of data... I also evaluate the scope and importance of my findings for Andean culture researchers,” he explained to Newsweek.

Eventually, though, Menegat’s research led him to a singular startling conclusion. It seemed that Machu Picchu had been constructed in a spot that most modern builders would steadfastly avoid: right on top of a series of tectonic faults. In fact, an entire network of cracks in the Earth’s crust seemingly ran beneath the city.

And according to Menegat, these faults vary in size. Indeed, while some of these breaks are little more than fissures, others stretch considerable distances beneath the mountains, with one particularly impressive example clocking in at more than 100 miles in length. A number of the faults also travel from northwest to southeast, while others run from northeast to southwest.

In fact, there’s so much geological activity here that five separate faults converge beneath Machu Picchu – creating an ominous X to mark the spot. And Menegat believes that this is unlikely to be a coincidence. Instead, he has argued that the tumultuous terrain is integral to the structure of the city itself.

While studying Machu Picchu, you see, Menegat observed that all of its main structures were built in alignment with the faults beneath the city. “The layout clearly reflects the fracture matrix underlying the site,” he explained in a press release from the Geological Society of America. And, shockingly, the mountain stronghold of the Incas is not the only settlement to have been built in such a manner.

Yes, Menegat discovered that a number of additional Inca cities also appear to be aligned along geological features. The ruins of Ollantaytambo – which lie less than 20 miles from Machu Picchu – are also believed to be located at the intersection of several tectonic faults. And 50 miles to the east at Pisac, a similar underlying structure can be found.

Menegat even claims that the Inca capital of Cusco was once constructed in alignment with the geological faults beneath the city. But why would these ancient people have chosen to build their settlements in such a way? Could it be the result of an age-old superstition, or perhaps even a choice with ritualistic connotations?

Well, Menegat believes that Inca culture actually had nothing to do with it. On September 23, 2019, the researcher presented his findings at the annual meeting of the Geological Society of America in Phoenix, Arizona. And during his talk, the researcher put forward a novel explanation: the Incas actually used the faults to lighten the physical load of building cities.

Yes, according to Menegat, the Incas specifically sought out areas of geological turmoil as locations for their cities. Since the stoneworkers who built the famously perfect walls were experts at their craft, the specialist claims, they knew that the fractured rocks found above tectonic faults would provide the perfect building material.

“Where faults intersect, the rocks are even more fractured,” Menegat told Newsweek. “Therefore, they are places that have more loose blocks on the surface, and [these are] also places where [the rocks] can be easily removed to build terraces and buildings.” That wasn’t the only advantage to constructing cities on these sites, however.

Menegat has gone on to explain that the fractured rock was also naturally set into geometric shapes such as hexagons and triangles – meaning the materials should have slotted together more smoothly. And if the pieces of stone were not the correct shape, then their fragile nature would have made it easier to cut them down.

“The intense fracturing there predisposed the rocks to break along these same planes of weakness, which greatly reduced the energy needed to carve them,” Menegat explained in the press release. In fact, in the geologist’s opinion, the construction of Machu Picchu would have been “impossible” without these conditions.

However, Machu Picchu’s position on top of several tectonic faults didn’t just make the workload easier. According to Menegat, this specific geology also funneled melted ice and precipitation towards the city, which in turn provided a ready source of clean water to the community in spite of the inaccessible mountain location.

“The Andean world is inhospitable,” Menegat told Newsweek. “Here, human life is possible only in a few places where water drips through fractures. The Incas knew to follow this criterion, which allowed them to establish networks of settlements in this kind of oasis of habitability provided by the faults and fractures.”

Owing to the water that came from the mountains, then, the Incas didn’t need to build in the low valleys – thus reducing the risk of danger from rockfall and flooding. And these unlikely but surprisingly sustainable cities were so successful that in total they were able to support a population of some ten million people.

But Menegat believes that the fractured rock beneath Machu Picchu had yet another purpose. While heavy rain was sometimes a problem even this high up in the Andes, the geology of the region could have provided natural drainage and so helped to protect the site from flooding. In fact, this feature may well have prevented the city from falling further into ruin after it was abandoned.

“About two-thirds of the effort to build the sanctuary involved constructing subsurface drainage,” Menegat explained in the press release. “The pre-existing fractures aided this process and help account for its remarkable preservation. Machu Picchu clearly shows us that the Inca civilization was an empire of fractured rocks.”

Fascinatingly, Menegat also revealed that the Incas had their own way of describing the tectonic activity on which their cities were built. “There is a Quechua word for large fractures,” he told Newsweek. “As the great Peruvian writer José Maria Arguedas said, the Incas called the fractures that crossed the mountains ‘quijlo.’ Geologists call them faults.”

But does this mean that the people who built Machu Picchu had an incredibly advanced comprehension of geology for the time? Well, while they may not have known the cause of tectonic faults, Menegat believes that they could definitely spot them. “The Incas knew how to recognize intensely fractured zones and knew that they extended over long stretches,” he continued.

Amazingly, then, the Incas’ knowledge of faults therefore enabled them to build structures that were to last for more than 550 years. But just as researchers such as Menegat are beginning to understand the secrets of Machu Picchu, the ruins are more at risk than ever. If plans to construct an airport just a few miles away are carried out, you see, the hub would bring dangerous numbers of visitors to the already crowded site. And although archaeologists are petitioning against the development, the future of the ancient city continues to hang in the balance – for now.