After An Earthquake Shook This Aztec Pyramid, A Stunning Secret Emerged Inside Its Crumbling Walls

The site in question is known as Teopanzolco and can be found in central Mexico. It contains several celebrated historic structures, so experts were keen to assess its condition after the devastating September 2017 tremor. Scholars from Mexico’s National Institute of Anthropology and History (INAH) kicked off the investigations. But nothing could have prepared them for what they would find.

Atop the pyramid of Teopanzolco, the damage was clear. But when the team dug pits in an attempt to stabilize the fragile monument, they stumbled upon a hidden secret lurking within the ancient walls. Something, it seemed, had been buried here long ago – before even the Aztecs broke ground.

So, what was this secret lost many centuries ago – only to be revealed as an earthquake tore through the land? And can it teach us something about the people who once called this part of Central America home? The truth is a fascinating journey through the world of the Tlahuica – a group poised to create the foundations for the famous empire which would succeed it.

Although Teopanzolco is commonly associated with the Aztecs today, it was actually founded by the Tlahuica. Unfortunately, little is known about this ancient culture, but it’s believed that they arrived in the region now known as Morelos in the 12th century. And around that time, they founded Cuauhnahuac – now the city of Cuernavaca.

According to the website Indigenous Mexico, the Tlahuica inhabited around 50 separate city states spread out across Morelos. But as the years passed, a more powerful empire began to grow in the north. Based out of the city of Tenochtitlan in what is now Mexico City, the Aztecs were quickly becoming the region’s dominant power.

Initially, it seems, the Tlahuica were regarded as equals to the Aztecs in their own right. But eventually, in 1427 the emperor Moctezuma Ilhuicamina conquered Cuauhnahuac and the other city states – incorporating them into his growing kingdom. At the same time, he also took control of the complex at Teopanzolco.

Today, experts believe that Teopanzolco once stood at the heart of Cuauhnahuac, although the ceremonial center of the city was later moved elsewhere. And although the site was initially built by the Talhuica, most of the ruins and relics found throughout the complex appear to date from the Aztec era.

But in a place that is already so fascinating, what kind of secret could have wowed archeologists the world over? Well, at Teopanzolco, a number of different buildings can be spotted scattered across the site, which sits on the outskirts of the modern city of Cuernavaca. While some are little more than low-lying platforms and staircases, others are somewhat more substantial.

The real showstopper, though, is the structure known as the Great Platform – the centerpiece of Teopanzolco. According to Smithsonianmag.com, work on this pyramid-shaped building began at the start of the 13th century. And at one point, its basalt foundations would have been covered in layers of plaster painted with bright designs.

Now, of course, all that is long faded – leaving only ruined stonework behind. Though that hasn’t stopped Teopanzolco from remaining one of the most significant Aztec sites in Central America. In fact, the twin temples that stand on the Great Platform are an early example of an architectural style that would be repeated across the empire.

On the northern side of the Great Platform, the ruins of a temple dedicated to the rain god Tlāloc can be found. Meanwhile, on the southern end, another structure was once used to worship Huītzilōpōchtli – a deity of war. Below them, a pair of parallel staircases would have provided access to both chambers.

Later, the Aztecs would use the same twin design when constructing the Templo Mayor – the main temple at Tenochtitlan. And for hundreds of years, these structures would serve as focal points at the heart of their communities. But then in the 16th century the Spanish conquistadors arrived in Central America, and they soon brought the empire to its knees.

For centuries, Teopanzolco stood abandoned – a shadow of its former self. Then finally in 1910 it was rediscovered by supporters of the revolutionary leader Emiliano Zapata. In their standoff against the Mexican government, they used the old temple complex as a makeshift base and positioned cannons to attack federal forces in Cuernavaca.

As violence erupted at Teopanzolco, the soil that had covered the ancient site began to shift. And before long, the Aztec stonework beneath became exposed. A few years later the first archeological investigations began – followed by a series of more comprehensive digs. Yet somehow, all of them missed what an earthquake would later reveal.

At 1:14 p.m. on September 19, 2017, a powerful quake tore through central Mexico which measured 7.1 on the Richter scale. And by the time that it was over, a number of buildings across Morelos and the neighboring state of Puebla were in ruins. But it wasn’t just modern, urban structures that were affected.

More than 200 miles southeast of the epicenter of the quake, the ancient pyramid complex at Monte Albán sustained significant damage. Thought to be one of the oldest settlements in Mesoamerica, experts believe that the city was an important cultural center some 2,000 years ago. But according to Lonely Planet, it was abandoned some time between 700 and 950 A.D.

According to the World Monument’s Fund, as many as 15 buildings at Monte Albán and the neighboring site of Atzompa were damaged in the devastating quake. And emergency work had to be carried out on five of the structures to prevent them from collapsing. Meanwhile, some 300 miles to the northwest, the complex at Teopanzolco was also suffering.

The Great Platform had been shaken to its very foundations thanks to the tremors which had ripped beneath it. In a statement from INAH, archeologist Bárbara Konieczna explained, “... The pyramid suffered a considerable rearrangement of the core of its structure.” But as experts mourned the damage, they could not have predicted what was to come.

According to the statement, the destruction was predominately centered around Teopanzolco’s most famous structures. It read, “The most serious damage was located in the upper part, where the temples of Tlāloc and Huītzilōpōchtli are located. There, the floor between the two shrines sank and tilted – endangering its stability.”

In order to assess the extent of the devastation, archeologists initially used a georadar device to scan the damaged structure. But eventually, they realized that they would need to dig down into the Great Platform if they wanted to get the full picture. So, they created two wells – one inside the temple of Tlāloc and another in the passage between the two structures.

It was there – beneath the Aztec ruins of Teopanzolco – that the team discovered something completely unexpected. Concealed beneath the later structure was another, hidden building. So, what exactly was this mysterious relic? And how long had it been buried for? Well, as they worked to uncover it, archeologists realized that it was even older than the pyramid itself!

Just over six feet beneath the Great Platform, the team found another earlier temple – previously undiscovered by the archeologists who had studied the site. And in a fascinating twist, its architecture appeared to echo that of the structure which can be seen today. Like the newer building, it also featured walls made out of two layers of stucco-coated stones.

Measuring around 20 by 13 feet, the temple is believed to date from between 1150 and 1200 A.D. That means it was constructed before the emperor Moctezuma Ilhuicamina brought Teopanzolco under Aztec control. And as such, it is likely to be a relic from the earlier days of the complex – when the Tlahuica were still in charge.

Like the building above it, experts think that this earlier structure was also used for the worship of Tlāloc: the god of rain. But that’s not all. According to the INAH statement, there might also be a Tlahuica-era oratory dedicated to Huītzilōpōchtli beneath its later counterpart. In other words, there could well have been twin temples on the site long before the Aztecs arrived.

Before this discovery, it was believed that the Great Platform at Teopanzolco was simply one example of many twin temples found across the Aztec Empire. But now, there is evidence to support the idea that the builders of structures such as the Templo Mayor at Tenochtitlan were actually copying an older Tlahuica design.

Konieczna explained in the statement that this latest discovery completely changed the chronology of Teopanzolco. Furthermore, she added, “It is not that the Mexica contributed that architectural style to this region. On the contrary, the Tlahuica constructions inspired them to build the Templo Mayor.”

But despite the age of this newly-discovered temple, archeologists were still able to learn plenty about what it would have looked like in its prime. Unlike the twin temples at the Templo Mayor, for example, the Teopanzolco structure is missing its ceiling – suggesting that it was made from a perishable substance.

It seems that the high humidity in the region has wreaked havoc on the temple’s stucco walls over the years. And in many places they have almost completely worn away. Thankfully, though, experts were able to salvage some fragments of the ancient material – ensuring that they will be preserved for posterity.

Archeologists who excavated the site pointed out that the temple floor was also coated in stucco. But beneath that, they found a layer of what’s known as tezontle – a type of volcanic rock that is often used in construction projects across Mexico. Further down still, there was a thin sprinkling of charcoal, although its purpose remains unknown.

But the earthquake of 2017 didn’t just reveal treasures of an architectural nature. In the ruins of the newly discovered temple, archaeologists also found a censer – or incense burner – covered in Tlahuica designs. And alongside this, they unearthed a number of ceramic fragments which were left behind by the people who once lived and worshiped here.

According to the INAH statement, the team discovered a substantial deposit of coal at the temple site, too. Could it be the residue from a mysterious, smoke-fueled ritual once conducted here? Or perhaps it is debris left over from the building’s destruction? Interestingly, there’s even speculation that the material could have been created by another, as yet unknown, disaster.

Certainly, it seems as if something must have occurred to inspire the construction of another temple to Tlāloc on top of the original design. But according to Koniecza, that wasn’t necessarily the case. It was apparently relatively common practice for the Tlahuica to use older buildings as foundations for new ones.

Interestingly, this isn’t the first time that a natural disaster has revealed something of great archeological interest. In September 2003, for example, a devastating wildfire tore through moorland in North Yorkshire, England. And although it destroyed vast swathes of vegetation, it also exposed a new and exciting landscape for the first time.

On the now-bare heathland, archeologists were able to spot a number of features – including rock art and field systems dating back to prehistoric times. The fire also uncovered traces of military features from the 20th century as well as various features associated with the region’s industrial past. Meanwhile, further south in Somerset, extreme floods have sometimes had a similar effect.

In fact, the county of Somerset is rumored to be one of the lowest-lying regions in the U.K. – making it exceptionally prone to flooding. Though while there are plenty who dread these destructive conditions, they also provide an unexpected boon for the region’s archeologists. As the water levels rise, you see, historic landscapes such as Saxon settlements become clear.

And across the sea in Ireland, a 2017 storm dubbed Hurricane Ophelia revealed something startling in the southeasterly region of Co Wexford. There, strong waves battered the coast and caused soil to drop away – exposing a set of human remains. Locals had initially worried that some poor, unfortunate soul had been fatally injured in the bad weather.

Before long, though, it became apparent that the remains were far older than the 21st century. Experts actually believe that they could date back to the Iron Age! Archeologists also found evidence that the individual had been interred at the site – rather than washed in from the sea. Amazingly, this makes it only the second ancient burial ever discovered in the region, according to the Ancient Origins website.

In fact, it seems as if the British Isles are a particular hotbed of archeological treasures revealed by extreme conditions. One year before Hurricane Ophelia, another storm battered the Orkney islands off the eastern coast of Scotland. And in the resulting erosion, an intricate Pictish carving was revealed.

So, what else might be waiting beneath the earth – only to be revealed when a natural disaster strikes? Back in Mexico, researchers are making the most of this new insight into the complex at Teopanzolco. But an archeologist who worked at the site called Georgia Yris Bravo López cautioned that further study is needed to fully understand the structure beneath the Great Platform.