The hill has been there for as long as anyone can remember.
It rises gently above the city of San Andreas Cholula in the Mexican state of Pueba.
Blanketed in grass and wild vegetation, crowned at its summit by a Catholic church whose white towers are visible for miles across the high plateau.
Tourists photograph the church.
Pilgrims climb the winding path to it.
Local families spread blankets on its lower slopes in the afternoon light.
On a clear day, you can see the snow cap of Popo Cateepil in the distance.
And the hill sits in the foreground looking utterly unremarkable.
Just another feature of a landscape that has known human settlement for 3,000 years.
And almost none of those visitors realize they are standing on the largest pyramid ever built on Earth.
Not the tallest, the largest.
By volume, the structure beneath that hill contains 4.
45 million cub m of material.
The Great Pyramid of Giza, which has served as the world’s definitive symbol of monumental construction for 4,000 years, has a volume of approximately 2.
5 million cubic meters.
Cholula is nearly double that figure.
The structure beneath that quiet grass-covered hill in central Mexico is bigger by volume than anything the ancient Egyptians ever built.
It is bigger than anything the ancient Romans ever built.
It is bigger than any structure that has ever been constructed anywhere on the surface of this planet by any civilization at any point in recorded history.
And for centuries, the Spanish colonial administration that governed Mexico did not recognize it as a pyramid.
Neither [clears throat] did most of the world.
The structure was so thoroughly disguised by vegetation, by centuries of gradual covering, and by its own unusual proportions that when concistadors arrived in 1519, they built a church on what they assumed was a natural hill.
My name is Marcus Reed, and what archaeologists have been pulling out of the tunnels beneath that church is forcing historians to revise what they thought they understood about ancient Meso America.
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We cover discoveries like this every week, and this one goes deeper than most people know.
The city of Cholula sits approximately 6 km west of Pueba in the high volcanic plateau of central Mexico, roughly 2 hours east of Mexico City at an elevation of about 2,200 m above sea level.
This is a region of rich agricultural land, volcanic mountains on the horizon, and layered archaeological memory built up across millennia of continuous human habitation.
The pyramid sits at the geographic heart of the city, straddling the boundary between the two municipal districts of San Andreas Cholula and San Pedro Cholula.
A division whose historical roots reach back to the 12th century when the Toltech Chich-ime people arrived, conquered the region, and pushed the existing inhabitants southward.
The formal name of the structure is Tlachiwalte.
This nawat word translates literally as artificial hill or handmade mountain.
And it was the name the Toltech Chich people gave to the pyramid when they arrived, explicitly acknowledging that the hill they were looking at was not a product of geology, but of human labor.
The city’s own name, Cholula, derives from the ancient Natal word Cholulan, which translates as place of refuge or place of those who fled.
Both names given centuries apart by different peoples point to the same essential quality of this place.
It has always drawn human beings toward it for safety, for worship, for burial, and for the kind of collective memory that requires a fixed physical point on the landscape to hold it.
At its height, between roughly the 3rd century BC and the 8th century AD, Cholula was one of the great cities of prehispanic Mexico.
Home to an estimated 100,000 people and the second largest urban center in Meso America after Teotiwakan, the cultural connections between Cholula and Teotiwakan were extensive.
Archaeologists have identified close similarities in pottery styles, artistic techniques, and architectural methods between the two cities, suggesting sustained trade networks, mutual religious influence, and possibly the movement of crafts people and architects between them.
Both cities experienced sharp population declines in the 8th century AD, part of a broader regional disruption that marked the end of the classic period in central Mexico and still has no single agreed upon explanation.
When Cholula’s population began to fall, the pyramids function shifted, but did not end.
Active construction on the structure had ceased, but the site continued to be used for burials and ceremonies by the communities that remained.
The Toltech Chich people, who arrived from their previous capital in the 12th century, found the structure largely overgrown, redirected primary religious activity to a new temple elsewhere in the city, but did not abandon the pyramid.
Historical records describe a Chi-Ch lord named Aquetszal Amapan who was said to reside at the Great Pyramid, an indication of its continued political and spiritual significance even after it had ceased to function as the city’s main ceremonial center.
By the time Spanish forces arrived in 1519, the pyramid was buried deeply enough under accumulated vegetation and soil that it read as a natural feature of the landscape.
Nearly 1,600 years of continuous occupation had produced a structure so thoroughly embedded in its environment that the colonizers who conquered the city walked across its flanks without realizing what they were walking on.
Construction of the Great Pyramid of Cholula began in approximately the 3rd century BC and continued through successive phases until the 9th century AD.
That span of more than a thousand years of active building makes it one of the longest construction projects in the history of any civilization anywhere.
And the way it was built is in many respects as fascinating as the final structure itself.
The pyramid did not grow by expansion outward from a single plan.
It grew by enclosure.
Each successive generation of builders wrapped a new layer around the existing structure, burying the previous pyramid inside the new one.
Archaeologists describe this construction method by comparison to a Russian nesting doll.
At the center of the current pyramid, preserved intact within the tunnel network are the walls and rooms of every earlier version.
When you walk through the tunnels today, you are not walking through a single structure.
You are walking through multiple pyramids that have been enclosed inside one another across a span of,200 years.
The earliest structure on the site designated building A and also called Lacer dates to pre- Teayoti Wakan times.
It was built primarily of adobe, sundried mud brick produced from the local clay soils and its design reflects an early but already sophisticated understanding of both engineering and sacred orientation.
Building A was dedicated to Ketzel Quaddle, the feathered serpent deity whose worship would remain continuous at this site through every subsequent phase of construction across changes of ruling group, changes of architectural style, and changes of political power.
The feathered serpent survived all of it.
The second major construction phase, building B, known as the pyramid of the painted skulls, was constructed between approximately 200 and 350 AD.
This phase introduced the Talud tabo architectural style, a system of alternating sloped lower panels and vertical upper table that became one of the defining architectural signatures of the classic period in central Mexico and appears across multiple Mesoamerican sites in various forms.
Building B had seven stepped levels with walls finished in a lime smoothed plaster that served as a painting surface.
Those walls carried murals depicting ceremonial scenes, figures engaged in ritual activity, evidence of a sophisticated iconographic program that communicated religious meaning to everyone who could see it.
Building F, the third major phase, dates from approximately 500 to 700 AD and represents the most technically complex construction to date.
This phase used stone rather than adobe for its primary structural elements, including a multi-level stairway facing west and introduced a decorative mosaic program that imitated the texture of a woven palm mat through carefully shaped and placed stones.
The engineering precision required to produce a consistent textile-like pattern across the face of a large architectural structure in cut stone speaks to the level of specialized craft knowledge that the Cholula builders had accumulated by this period.
The courtyard complex on the south side of the pyramid, known as the courtyard of altars, and excavated between 1967 and the 1970s, added another dimension to the site’s ceremonial function.
This area served as a space for large public ceremonies and the formalization of political power transitions.
Its altars and platforms were painted in bands of red, blue, yellow, and black with aquatic imagery.
the visual language of water and rain that would run as a constant thread through Cholula’s sacred life from its earliest phases to the present day.
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And now, let’s go inside the mountain.
For most of the colonial period and well into the first decades of the 20th century, the Great Pyramid of Cholula was not formally recognized as a pyramid by the institutions of Mexican archaeology.
Its exterior surface softened across centuries by the growth of vegetation, the accumulation of windblown soil, and the deliberate earthn coverings added during later construction phases looked indistinguishable from the naturally occurring hills scattered across the Pueblo Valley.
The church built on its summit in 1594, the deestra seora deio served simultaneously as an active Catholic sanctuary and as an inadvertent marker of the site’s archaeological significance that would not be properly interpreted for another three centuries.
That changed in 1931 when architect Ignasio Marina received authorization to begin cutting exploratory tunnels into the structure.
Marina’s working hypothesis was that the hill concealed a man-made pyramid of significant dimensions.
His tunnels were designed to confirm or refute that hypothesis by exposing cross-sections of the interior, allowing archaeologists to determine whether they were looking at natural geological deposit or layered human construction.
What Marina found and what the teams that followed him continued to find over the next two decades was far beyond his initial projections.
By 1954, the tunnel network beneath the Great Pyramid of Cholula had reached a total length of nearly 8 km or approximately 5 miles.
To put that in physical terms, you could walk these passages end to end and cover a distance greater than the entire diameter of Manhattan Island.
And this network was not the result of random exploratory digging.
It was systematic work following the internal logic of the pyramid’s construction, tracing the boundaries between successive building phases, exposing interior wall surfaces, mapping the architectural sequence of the structure from its earliest core outward.
The tunnels revealed, among other things, that the interior was not solid fill.
There were interior chambers, some of them clearly designed as ritual spaces with finished wall surfaces, preserved plaster, and in some cases, traces of pigment.
There were interior stairways connecting construction levels that had never been intended for external visibility.
There were areas that appear to have functioned as transitional zones and ceremonial processions, spaces through which priests or officients moved between one sacred context and the next.
The pyramid was not merely a raised platform for a summit temple.
It was itself a structured ceremonial environment with an interior life as intentional as its exterior.
Of the 8 km of tunnels, approximately 800 meters are open to the public today.
The remainder are maintained for ongoing archaeological access but not for general visitation.
Partly due to conservation requirements and partly because the continued presence of the active church above creates structural constraints on any intervention in the pyramid’s upper sections.
What visitors walk through represents roughly 10% of the total tunnel network.
The remaining 90% continues to yield material yearbyear as restoration and excavation work proceeds.
And what the most recent phases of that work have found is where the story takes its most startling turn.
The latest round of excavation and restoration at Cholula has produced a sequence of finds that represent collectively one of the most significant bodies of new evidence in contemporary Mesoamerican research.
The first of these was structural.
During work categorized as the fifth stage of the construction sequence, excavators uncovered the adobe core of the pyramid’s earliest phase, building A, dating to the classic period between 100 and 600 AD.
What made this find significant beyond its age was its condition.
The adobe bricks of the original construction sealed inside the later construction phases for over 15 centuries were preserved in a state of extraordinary clarity.
Their surface texture was readable.
The composition of the clay was analyzable.
The patterns of their laying showed the organizational methods of the original builders with a precision that is rare in any archaeological context.
This was not a fragment or a residue.
This was the original heart of the pyramid, intact and accessible.
Near one of the main stairways, excavators also uncovered a series of prehispanic brazers, ceramic vessels designed for burning offerings.
The significance of their location is not accidental.
A brazier placed at the base of a stairway that ascends toward a sacred summit makes a specific statement about what that ascent meant.
The act of climbing was itself a ritual act.
Fire marked the transition from ordinary ground level space into the sacred territory of the pyramid’s upper reaches.
The use marks on these brazers indicate repeated firing over an extended period, suggesting not a single ceremonial event, but a sustained practice maintained across years or possibly decades of regular ritual activity at this exact point on the structure.
The discovery of alok sculpture in recent excavations adds another layer of confirmed context.
Slaloc, the rain god, is one of the oldest continuously documented deities in the Mesoamerican record with iconographic evidence of his worship appearing across a span of more than 2,000 years and across virtually every major Mesoamerican civilization.
At Cholula, in a city dependent on seasonal rainfall for the agriculture that fed a population of 100,000 people, TLock’s presence was not incidental.
It was existential.
The sculpture confirms what the burial evidence would make explicit, that this pyramid’s sacred function was deeply and continuously entangled with the management of water, drought, and the human community’s relationship to the forces that controlled its survival.
because over 400 human burials have now been identified within and immediately around the pyramid complex.
The majority of these date to the postclassic period after the main phases of construction had ended, indicating that the site retains sufficient sacred significance to serve as a preferred burial location for centuries after it had ceased to function as an active temple.
Among the remains, excavators identified victims of human sacrifice, including individuals showing signs of decapitation and other forms of ritualized death.
These were not spontaneous acts.
They were structured, formally organized, ritualized events carried out according to established protocols intended to maintain the relationship between the living community and the divine powers the pyramid represented.
And then there were the children found beneath the courtyard of altars.
Under the slab flooring of the courtyard, excavators discovered the remains of eight individuals, including several children, placed inside ceramic pots.
The care of the placement is unmistakable in the archaeological record.
These individuals were arranged deliberately, enclosed in formed ceramic vessels and deposited beneath the floor of the city’s most important public ceremonial space.
The interpretation that archaeologists have advanced is consistent with documented Mesoamerican ritual practice recorded at Teayotiwakan and in Aztec religious cotices.
These children were offered to Tlalaok during periods of drought sent as messengers to the rain deity.
Their tears understood as a form of supernatural appeal for water.
The community that placed them there was not acting in a spirit of cruelty.
It was acting in a spirit of desperation and faith.
making the most significant offering it could conceive of to a god it believed held its survival in his hands.
At the southwest corner of the pyramid, excavators also found the disarticulated remains of at least 46 individuals at a dedicated altar area representing men, women, and children across multiple age groups.
The disarticulation, the separation of bones from one another after death, indicates a secondary burial practice in which individuals who had died elsewhere were later brought to the pyramid for final deposition near the sacred structure.
Each set of remains represents a decision made by living people about where their dead should rest.
And every one of those decisions pointed here.
The site museum offers models of the pyramids layered construction, recreations of the murals found in the tunnel network, and displays of ceramics recovered from the various excavation phases.
But even the museum’s comprehensive presentation represents only a fraction of what the pyramid contains.
The sections beneath the active church remain unexavated.
Whatever additional chambers, burials, ritual spaces, and architectural evidence exist in those sealed areas will remain inaccessible until either new non-invasive imaging technology provides a way to see through the material without disturbing it, or the complex relationship between archaeological authority and the ongoing religious life of the site allows for new arrangements.
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What is already known is extraordinary.
What remains sealed is potentially more so.
When Herman Cortez and his forces arrived in the Puebla Valley in October 1519, Cholula was still a functioning religious center of considerable regional importance.
The Cholula massacre that followed in the first days of the Spanish presence there in which thousands of the city’s inhabitants were killed effectively ended Cholula’s independence as a political entity and began the transformation of its sacred landscape according to the priorities of the colonial administration.
The church placed on the summit of the pyramid in 1594, theia seora deios, was not positioned there in ignorance of the site’s significance.
The summit of the pyramid had been a sacred high point for over a thousand years.
Building a Christian church at the highest visible point in the city was a deliberate statement of theological and political authority, executed with full awareness of the indigenous religious meaning that point on the landscape carried.
This practice was standard colonial policy across Latin America and the Caribbean.
Wherever indigenous sacred sites of high importance existed, Catholic structures were placed on or adjacent to them, absorbing the existing devotion into the new religious framework.
The result, four centuries later, is a site of extraordinary theological complexity.
A Catholic church that is an active place of pilgrimage and worship stands directly on the summit of a pyramid that was dedicated across its entire construction history to Ketzel and Slaloc.
The Catholic virgin venerated in the church above replaced an indigenous rain goddess named Chuknakia and the replacement was so thorough that the primary veneration date for Chuknakia, the 8th of September was kept without alteration as the feast day of the Virgin of remedies.
The ritual calendar was not destroyed.
It was overwritten with new names and new iconography while the calendar itself remained intact.
This layering creates the central archaeological tension that governs the entire site.
The church cannot be moved.
It is an active religious landmark with its own 400year history of Catholic significance.
And it sits directly over sections of the pyramid that have never been archaeologically examined.
The summit platform, the upper sections of the pyramid’s interior, and whatever ceremonial spaces existed immediately below the current church floor are effectively inaccessible by the standards of conventional excavation.
Non-invasive ground penetrating radar surveys have been conducted in some areas, and the data those surveys return suggest the presence of additional architectural features in the unexavated sections.
But the resolution of current imaging technology is not sufficient to replace the kind of information that careful excavation would produce.
What this means practically is that the 8 km of tunnels and the discoveries they have yielded represent the accessible portion of a larger site whose full extent and content remain unknown.
The pyramid that Ignasio Marquina began to map in 1931 and that researchers have continued to study for nearly a century since is an incomplete picture of an incomplete excavation.
We are reading a text with significant portions still sealed.
The Great Pyramid of Cholula is not a ruin in the way that most people use that word.
It is a functioning sacred site integrated into the living ceremonial calendar of the city that surrounds it in a way that has not been interrupted since the structure was first built.
On the 8th of September each year, the celebration of the Virgin of Remedies draws thousands of pilgrims to Cholula from across Mexico and beyond.
The night before the feast day, the streets and courtyards around the pyramid are lit by lanterns, and the city takes on a quality that is at once festive and reverent, a combination of popular celebration and deep religious obligation.
The ceremony maintains in its calendar placement and in much of its emotional content, the structure of the ancient veneration of Chuknakia, the rain goddess whose feast day fell on the same date.
The Catholic veneer is real and sincerely held.
But beneath it, older rhythms continue.
In May and June, the Bahada takes place.
The image of the Virgin of Remedies is carried down from the church at the summit of the pyramid in a formal procession and taken on a two-week tour through the neighborhoods of Cholula, visiting individual homes and gathering points across the city before being returned to her position at the top of the pyramid.
This is a ritual circuit, a ceremonial mapping of the city through the movement of its most sacred object, connecting the elevated sacred space of the pyramid summit to the ordinary ground level life of the community it presides over.
On the spring equinox, the Ketau ritual takes place at the base of the pyramid.
Poetry is performed.
Indigenous dance troops present ceremonial dances whose choreography preserves prehispanic movement traditions.
Musicians play.
Fireworks are set off in the evening, though access to certain areas of the archaeological zone is restricted during this event to protect exposed tunnel sections from vibration damage.
Tens of thousands of visitors attend, and in recent years, the event has drawn significant international attention as awareness of the pyramid’s historical importance has grown.
Three distinct ceremonies on three distinct kundrical markers, each rooted in different eras of the site’s history, each maintained continuously across whatever disruptions the intervening centuries produced.
The spring equinox honors the feathered serpent for whom the pyramid was originally built.
The September 8th festival honors the rain goddess whose function was transferred to the Catholic virgin without losing her calendar date.
The Bahada reenacts the movement between sacred highpoint and inhabited city that the pyramid’s spatial relationship to Cholula has encoded since the structure was first oriented and dedicated.
What the archaeologists working in the tunnels beneath this site are doing is not separate from those ceremonies.
They are the latest set of people in a continuous human relationship with this place that stretches back approximately 2,300 years.
The builders of building A in the 3rd century BC.
The architects of building B’s painted skull murals in the 2nd century AD.
The stone carvers of building F’s mosaic tudes in the 6th century.
The parents who placed their children in ceramic vessels beneath the courtyard of altars in hopes of ending a drought.
The Spanish colonizers who built their church on the summit in 1594.
The pilgrims who walk up that same hill every September 8th with lanterns.
and the archaeologists who spend their careers in 8 km of underground passages.
All of them are part of the same record.
The Great Pyramid of Cholula is the largest structure ever built by human hands.
Its volume dwarfs the Great Pyramid of Giza.
It was built across more than a thousand years by communities who believed that sustained collective labor on a sacred site was itself an act of devotion.
It contains within its tunnels the preserved physical evidence of 1,200 years of construction, ritual, sacrifice, art, and burial.
And in the section still sealed beneath an active church, it holds evidence that no living archaeologist has yet seen.
This is a structure that has been continuously present in human life for over 2,000 years.
We have been excavating it seriously for less than a century.
Every season of work produces new material.
The transcript of what this pyramid contains is still being read.
Remember, my name is Marcus Reed, and if you learned something new today, ensure to subscribe and also leave a comment about what shocked you most about the Cholula Pyramid.
I’ll see you in the next
