A pyramid.

That’s right, while prepping the site they stumbled across the ruins of a large pyramid. Archaeologists have since come in and collected dozens of artifacts and they continue to study the site closely.

To keep the area safe, the archaeological authorities approved a construction project that built a large wall around the pyramid site. This wall is 43 meters (141 feet) long and 11.7 meters (38 feet) tall.

The structure itself has been determined to be part of a settlement known as San Miguel, which is from sometime between the Epiclassic period (650-950 CE) and the late Postclassic period (1350-1519CE). The area during these times was controlled by the Metzca lordship.

This area continues to be excavated and studied to learn more about it. This process will likely go on for many years as the pyramid structure is quite large and impressive.

Experts will also want to scan the surrounding areas to see what other types of structures or artifacts can be discovered. This type of scan is often done using LiDAR (Light Detection and Ranging), which can revel things hidden under the Earth.

Mexico’s National Institute of Anthropology and History is running the investigation and studying the artifact that have already been unearthed.

There is history hidden just below the ground.