Archaeologists have seen a pattern emerge throughout human history. First, there are small settlements. And by the time bigger buildings are constructed, the society is more developed – and more stratified.

But a newly discovered Maya site suggests that these ancient people were creating extraordinary monuments before they even had a centralized form of government. That contradicts the idea that Maya civilization developed gradually, as other scientists have suggested. It’s also a testament to the feats that humans can achieve by working together.

The site, Aguada Fénix, was built in Tabasco, Mexico around 1000-800 B.C., making it the oldest monument built by the Mayan people. It’s also the largest monument found so far. But, surprisingly, Aguada Fénix doesn’t have indicators of marked social inequality that are typical at sites of this magnitude or from later periods. Instead, it’s likely that the Mayans built such a large structure by working together voluntarily, the researchers report June 3 in Nature.

The team identified 21 ceremonial areas, each made of a circular or square mound with a long rectangular platform. The largest of those, Aguada Fénix, is about 50% bigger than the next largest site, says Takeshi Inomata, an archaeologist at the University of Arizona who discovered Aguada Fénix along with his colleagues.

So, how did such a massive structure go undetected for so long? It kept a low profile. Literally. The largest rectangular platform spans nearly 1/4 of a mile but is only 10-15 meters tall. “It’s big, but it’s big horizontally,” says Inomata. From the ground, he says “it almost looks like part of the natural landscape.”

The main feature of the Aguada Fénix is a man-made platform of clay and dirt with nine causeways leading towards it. People may have marched along these routes during ceremonial processions and held feasts or parties on the platform, the researchers speculate. The team also unearthed several jade axes that were likely presented during a ceremony and then buried in the platform as part of a ritual.

However, the team didn’t find evidence of palaces, large buildings, or colossal statues of thrones or rulers –telltale signs of significant social inequality – at Aguada Fénix. That was surprising, says Inomata. That these indicators are missing at Aguada Fénix suggests that the monument was likely constructed by people working together voluntarily.

The team also didn’t see evidence of large residential areas, suggesting that the builders of the monument lived a somewhat mobile lifestyle. These ancient people likely moved around to fish, hunt, or gather food, the researchers say. However, remnants of maize on grinding stones suggest that the Mayans were also growing maize around the time when Aguada Fénix was built.

The discovery of Aguada Fénix was possible thanks to a technology called LIDAR, which uses laser beams that bounce off the ground to create a 3D map of the Earth’s surface. Inomata and his team were looking at LIDAR images from 2017 of a site when they noticed what looked like another site. When they surveyed that other site in 2019, they discovered Aguada Fénix, the largest and oldest Mayan monument found to date.

To Inomata, the monument shows the “potential of people who organize themselves without a centralized government to achieve an enormous project that involved a lot of innovation.”

“[Aguada Fénix] forces us to rethink the process of social change,” he says.