A group of workers in Andalusia, an autonomous region in Spain, happened upon a surprising discovery while they were performing upkeep on water supplies: an ancient necropolis that could date back as far as the 5th century BCE.

The Guardian reports that the necropolis may have once been used by the Phoenicians, who spread their roots across the eastern portion of the Mediterranean. The necropolis was discovered in Osuna, a town primarily known to those outside Spain for acting as a location for the TV series Game of Thrones.

Osuna is also host to a number of previously discovered Roman ruins, including a necropolis that can be visited as a tourist site. And while sites such as that one are well known, it is still rare for finds like this one to be made in Osuna, a town so dense with history that it is also host to a Renaissance church, Baroque art, and more.

According to the Guardian, early examinations of the newly unearthed necropolis have turned up eight burial vaults, staircases, and spaces that may have once served as atriums. Mario Delgado, an archaeologist who led the survey of the find, told the Guardian that necropolises like this one are typically found in areas like Sardinia, which is far from Osuna.

But he cautioned that the new necropolis is hardly definitive, given that the Phoenicians and the Carthaginians were already known to have resided in what is now known as Osuna.

The find “doesn’t change history—but it does change what we’d known until now about the history of Osuna, and it could be a turning point,” he said.