Two University of Wyoming anthropology professors have discovered one of the oldest circular plazas in Andean South America, exhibiting monumental megalithic architecture, which refers to structures made of large stones laid upright without mortar. have been used.

Located at the Calakpoma archaeological site in northern Peru’s Cajamarca Basin, the plaza is made of large, vertically placed megalithic stones – a construction method not previously seen in the Andes. Associate Professor Jason Twohey, project lead, and Professor Melissa Murphy have been researching the topic since the project’s inception in 2015. Excavations at the plaza began in 2018.

Their paper, which reports new data on the oldest megalithic circular plaza in the northern Andes, is titled “A Monumental Stone Plaza at 4750 BP in the Cajamarca Valley, Peru,” and is published today (14 February) is published in Peru. Reviewed Journal Advances in science.

Radiocarbon dating dates its earliest construction to about 4,750 years ago during the Late Preceramic period, making it one of the earliest examples of such architecture in the Americas.

To better understand this timeline, the team carefully excavated within the plaza, uncovering artifacts related to past life and collecting charcoal samples for dating. All material residues were then cleaned, processed and analyzed in the laboratory.

“This structure was built about 100 years before the Great Pyramids of Egypt and about 100 years before Stonehenge,” Toohey says.

These dates indicate that Callacpuma’s circular plaza is the earliest example of monumental and megalithic architecture in the Cajamarca Valley — and one of the earliest examples of ancient Peru.

“It was probably a gathering place and ceremonial site for some of the earliest people living in this part of the Cajamarca Valley,” Tuohy added. “These people lived primarily a hunting and gathering lifestyle and probably only recently began growing crops and domesticating animals.”

The plaza is made up of two concentric walls and is about 60 feet in diameter.

The project is led by Toohey and Patricia Chirinos Ogata from the University of California-Santa Barbara. The team includes Murphy as well as undergraduate and graduate students from Peru and the United States.

Toohey is an anthropologist dedicated to taking a holistic and multidisciplinary approach to the field. He has conducted fieldwork in the Peruvian Andes since 2003.

“As part of our community outreach, we collaborate and work with residents on the Callacpuma site and in adjacent towns to inform them of our findings and their significance,” says Toohey. “We highlight the importance of cultural heritage and by working together, we can continue scientific research and help preserve this place.”