Many people defend the idea that the great pyramids of Egypt were built by an antediluvian civilization, by giants, or even by extraterrestrial beings. However, expressing this opinion in Cairo, the capital of Egypt, may cause discomfort or offense to an Egyptian. This is because, based on archaeological evidence, Egyptians firmly believe that their ancestors, the ancient Egyptians, were the true builders of these monumental structures. This view contradicts widely circulated theories around the world, which attribute the origin of the pyramids to unknown or otherworldly civilizations.
However, there are other pyramid complexes around the world whose builders remain a mystery. Unlike the pyramids of Egypt, there are no descendant peoples claiming responsibility for their construction, nor any records or concrete evidence pointing to the responsible parties.
When the Mexicas (or Aztecs) arrived there, the constructions already existed and were in ruins. They named the city “Teotihuacán,” which means “City of the Gods” in Náhuatl (an indigenous language of Mexico, spoken by the Nahua people).
Teotihuacán, located about 50 km from Mexico City, is one of the most visited and enigmatic archaeological sites in the country. Its pyramids impress with their grandeur, but despite its historical significance, very little is known about this city, which has more than 2,000 years of history. When the Aztecs discovered Teotihuacán, it had already been abandoned and in ruins for nearly a thousand years.
Teotihuacán emerged around the 1st century AD, but the identity of the people who built it and the original name of the city remain unknown. For this reason, the term “Teotihuacán culture” is used to refer to it. The absence of a written tradition from the time of its origin makes research on Teotihuacán a significant challenge. The city flourished between the 1st and 8th centuries AD, reaching its peak between 450 and 650 AD, when it housed up to 200,000 inhabitants. At the time, it was the largest city on the American continent and one of the largest in the world, with an area of about 82.6 km².
There are different theories about the growth and expansion of Teotihuacán. Some scholars assert that the city expanded mainly through trade, while others suggest that Teotihuacán was a militaristic state, with its expansion occurring through force. A plausible explanation is that Teotihuacán’s success was the result of a combination of factors, including trade, military power, and political alliances. The city was designed with remarkable urban planning, highlighted by its Avenue of the Dead, a central avenue approximately 5 km long, flanked by neighborhoods divided by straight streets. Along this avenue, various buildings of different types and sizes rise, with three standing out: the Pyramid of the Sun, the Pyramid of the Moon, and the Temple of Quetzalcoatl, dedicated to the feathered serpent god.
Pyramid of the Sun
The Pyramid of the Sun, with a height of 65 meters and a base of 222 meters by 225 meters, is the largest pyramid in Teotihuacán and the third largest in the world. Its name was given by the Aztecs, and the original name is unknown. The pyramid has five platforms, and at the top stood a temple, now disappeared, along with the paintings that decorated the exterior walls. The entire structure was covered with lime plaster, on which colorful paintings were applied, predominantly in red, blue, and white, depicting jaguar heads and paws, stars, and snake rattles. Only traces of these paintings remain.
The pyramid is solid, with no internal chambers or tombs. However, excavations conducted between 2008 and 2011 uncovered five cemeteries at different levels inside the pyramid. A cave was also discovered beneath the pyramid, accessible through an artificial tunnel. For a long time, it was believed that the cave was of natural origin, but recent studies suggest it was artificially constructed. This theory is supported by the discovery of chisels found in the tunnel and traces of handprints.
The deity to whom the pyramid was dedicated is still debated. Some researchers suggest that the pyramid was dedicated to Tlaloc, the rain god, whose images were found during excavations. Others theorize that the deity worshiped might have been some form of mother goddess, based on paintings found in the Tepantitla residential complex.
In 2013, while excavating a pit at the top of the pyramid, the statue of Huehueteotl, the god of fire, was discovered. The sculpture, the largest ever found in Teotihuacán, was located just 50 cm below the surface and is made of gray andesite stone. Standing 61 cm tall and weighing 190 kg, the statue depicts the god as an elderly man sitting cross-legged, with his hands on his knees, wearing a headdress and crowned with a brazier. The presence of Huehueteotl provides clues about some of the rituals performed at the Pyramid of the Sun, such as the “new fire” ceremony, which occurred every 52 years when the 365-day solar year and the 260-day calendar aligned.
Pyramid of the Moon
The Pyramid of the Moon, located in Teotihuacan, is 46 meters tall and has a base that measures 150 meters in width and 120 meters in length, not 120 m x 140 m. It is dedicated to goddess Chalchiuhtlicue, the goddess of water, storms, and fresh waters such as lakes, rivers, and springs, and is also associated with fertility and birth. There are indications that the pyramid went through several construction phases, with some sources suggesting up to 7 stages, but there is no conclusive evidence of seven other pyramids inside it, only chambers. Excavations have revealed human remains and artifacts, suggesting ritual sacrifices or significant burials.
The pyramid is surrounded by various structures, including 13 platforms, which likely served as altars, forming one of the most impressive plazas in Teotihuacan.

The Temple of Quetzalcoatl
Quetzalcoatl is one of the greatest deities of Mesoamerica. The name is formed from the words quetzal, the name of a bird from Central America, and coatl, which means “serpent,” thus translated as the Feathered Serpent god. His temple in Teotihuacan measures 65 meters by 65 meters on each side and is made up of 7 terraces richly decorated with heads representing feathered serpents, as well as shells and snails.
Recent interpretations suggest that Quetzalcoatl was the patron god of the Teotihuacan rulers and that the pyramid was related to the creation of time and the calendar. Since Quetzalcoatl was associated with the evening star, it is possible that the pyramid also honored the planet Venus. Tombs with human remains were found during various excavation phases of the temple. The tombs contained sacrifice offerings, but some had already been looted by thieves when they were examined. In a tunnel beneath the pyramid, researched in 2015, over 50,000 ritual objects were found, such as stone sculptures, precious stones, incense burners, blades, and obsidian tools—offerings placed in the 138-meter-long tunnel. The tunnel’s ceiling was sprayed with pyrite, a shiny golden metal. Anyone entering the tunnel with a lit torch would see the vaulted ceiling shining like a starry sky.

But who built Teotihuacán?
Despite its grandeur and historical importance, many aspects of its origin and the peoples who inhabited it remain shrouded in mystery. One of the main difficulties in understanding the origin of Teotihuacán is the lack of written records. Unlike other Mesoamerican civilizations, such as the Maya and Aztecs, who left codices and inscriptions, the Teotihuacans did not leave textual evidence that could clarify their history or identity.
Several theories have been proposed to explain who built Teotihuacán. One suggests that the Totonacans, a people who inhabited the coastal region of the Gulf of Mexico, may have been responsible for constructing the city. However, this theory lacks conclusive archaeological evidence and is not widely accepted by the scientific community. Another hypothesis points to a civilization that preceded the Maya and Aztecs, known as the Teotihuacans. This civilization would have developed an advanced culture, with knowledge in architecture, urban planning, and art, but left few traces of its identity. The lack of written records and the scarcity of direct archaeological evidence make the study of the origin of Teotihuacán’s builders a fascinating enigma for researchers.
Recent archaeological research has sought to uncover the mysteries of Teotihuacán. For example, excavations led by Nawa Sugiyama from the University of California, Riverside, revealed evidence of a large fire that destroyed part of the city. Charred walls and burned materials suggest that the city was destroyed by a violent event, possibly related to internal or external conflicts. However, the identity of those responsible for this event remains unknown. Teotihuacán exhibits unique characteristics that indicate sophisticated urban planning and complex social organization. The layout of the pyramids, temples, and residences suggests a highly structured society, but without records that could reveal details about its origin or identity. The city was divided into residential sectors, each with distinct characteristics, suggesting a possible social or functional division.
The mystery of who built Teotihuacán remains unanswered. The lack of concrete evidence and the absence of written records make this enigma one of the greatest challenges in Mesoamerican archaeology.
The Mysterious End of Teotihuacán

Teotihuacán had an end as mysterious as its origin. Around 650, the city began to lose population for unknown reasons. No new constructions were made, and neighborhoods were abandoned. The population reached around 75,000 inhabitants, just 25% of what it had been at the peak of its glory. It was still the largest city in the Valley of Mexico and one of the largest in Mesoamerica. The city seemed to have gradually lost its original importance as an economic center, until it could no longer sustain itself. By around 750, the urban area had been reduced to just 5,000 people. Teotihuacán had collapsed.
The most important buildings in the city center were set on fire, but most of the remaining neighborhoods suffered little to no damage. There are no signs of an external attack. Therefore, it is assumed that the inhabitants themselves caused the destruction in a ritual act, something similar to what the Olmecs did.
The buildings around the Avenue of the Dead were systematically destroyed by the city’s inhabitants, dismantled, and reduced to rubble. The last residents left the city at least a century after the center was destroyed. However, the city was never completely forgotten, becoming an important pilgrimage site. The Aztecs, in particular, revered Teotihuacán, believing it was the place where the world was created and where their gods were born.