A hidden temple was discovered by scientists from Mexico’s National Institute of Anthropology and History (INAH) while scanning the great Aztec pyramid Teopanzolco for structural damage, after a deadly 7.1 magnitude earthquake hit central Mexico last September, the BBC News reported.

INAH archaeologist Bárbara Konieczna said in a statement, that the earthquake caused a “considerable rearrangement of the core of [the pyramid’s] structure.”

The Teopanzolco site has been excavated since 1921, but it took a 7.1 magnitude earthquake to reveal a secret: a structure, buried for centuries, about six-and-a-half feet below Tláloc’s main two temples.

The newly discovered temple dates to about 1150 to 1200 C.E., while the main structure of the pyramid dates to between 1200 and 1521, indicating that later populations built over the older structures, as noted by Paredes of El Sol de Cuernavaca.

The Teopanzolco site originated with the Tlahuica civilization around 1200, which founded the city known today as Cuernavaca. During the 15th century, the Tlahuica people were conquered by the Aztecs, who took over construction of the Teopanzolco pyramids.

After the arrival of the Spanish conquistadors in the 16th-century, the site was abandoned only to be rediscovered in 1910.