The researchers have named this intriguing archaeological site, built from stones and earth, the Scorpion Mound. Located in the arid Tehuacan Valley in Puebla state, about 260 kilometers southeast of Mexico City, this complex may have served as both a ceremonial center and an astronomical observatory for observing the Sun, particularly during the summer and winter solstices.
The Scorpion Mound is part of a larger ceremonial and public complex covering 9 hectares. It contains at least 12 other mounds connected by a network of prehistoric irrigation canals, as reported by Arkeonews. These canals are part of one of the largest and oldest water management systems, which encompassed around 100 square kilometers of agricultural land.
What Did the Researchers Report?
Drone photography of the Scorpion Mound and GPS mapping confirmed that this is not a random pile of field stones. Scientists observed a carefully constructed complex.
The mound, approximately 62.5 meters long and 80 centimeters high, symbolically represents the scorpion deity Tlauizcalpantecuhtli, associated with Venus, rain, and fertility.
When viewed from above, the silhouette of a scorpion is unmistakable: the body, two elongated pincers, and a curved tail. According to archaeologist James A. Neely, the lead author of the study, such mounds associated with idol worship are quite common in North America, but they are rare in this region. He noted that this mound symbolizes a unique blend of “astronomical knowledge, ritual practice, and local agricultural traditions.”
While mapping the complex, researchers found that the direction from the scorpion’s stinger (the tip of the tail) to the left pincer forms a 65-degree angle to the east-northeast. This is where the Sun rises during the summer solstice. During the winter solstice, the sunset aligns with the scorpion’s tail when viewed from the left pincer.
Such geometry suggests that the mound was used as a solar calendar to mark the changing of the seasons. This information was vital in the semi-arid valley. “For ancient farmers, observing the solstices was not a luxury. It was essential for survival,” Neely explained.
The summer solstice marked, among other things, the beginning of the rainy season, signaling the right time for planting corn and other crops. The winter solstice marked the end of the season—a time for ritual offerings and ceremonies of gratitude.
Interestingly, during excavations, discovered ceramic vessels, incense burners, and fragments of figurines that indicated ancient ritual traditions.
Connection to the Cosmos
The symbol of the scorpion held deep cosmic significance for the ancient peoples of Mexico. In Aztec mythology, this creature was associated with Venus as the Morning Star—a celestial force embodying water, fertility, and renewal. This imagery can also be found in Cacaxtla, a nearby ceremonial center known for its vibrant frescoes depicting Venus and the scorpion.
Unlike the monumental in cities like Chichen Itza or Monte Albán, the Scorpion Mound reflects the astronomical knowledge of rural farmers rather than the elite. Its builders were likely villagers whose daily lives depended on the land and the sky.
The findings of the study were published in the journal Ancient Mesoamerica.