A 6,000-year-old necropolis in central Spain is forcing a radical rethink of who built Europe's first great tombs

Archaeologists working in Toledo, central Spain, have discovered what they believe is the oldest documented monumental necropolis in the interior of the Iberian Peninsula. This ancient site dates back to about the end of the 5th millennium BC (about 4300 to 4000 BC) and challenges a long-held theory that megalithic funerary structures were initially restricted to the coastline before spreading inland.

The prehistoric site, called Valdelasilla, sits on a hill overlooking the town of Illescas. It was discovered in 2020 and excavated during that year. Details of the research are in a paper published in the Cambridge Archaeological Journal.

Inside the ancient necropolis

The site contains a large circular chamber tomb measuring 6 meters across, surrounded by a large, ditched enclosure measuring roughly 36 meters in diameter. Around it are several smaller funerary chambers made from wood, clay, and compacted earth, and measuring 2 to 3 meters wide. Human remains from at least 46 individuals were found inside 11 of the funerary structures and dated using radiocarbon dating and computer modeling.

According to the research team, people used this site for generations, from the Late Neolithic period to the Chalcolithic (Copper Age). During its history, funerary practices changed, from the organized burial of individuals in the early days to collective tombs and secondary burials later on, where bones and skulls were deliberately arranged.

Valdelasilla is fascinating for more than just what was found buried in the ground. The study authors believe that the site represents a very early form of megalithic funerary practices, which evolved into the construction of massive monuments from giant stone slabs. Many of these megaliths can still be seen dotting landscapes across Europe.

"The necropolis, established in the late 5th millennium BC, shares many traits with other peninsular cemeteries associated with emerging megalithism in the northeast and southwest," wrote the team in their paper.

A new theory for megalith origins

Because Valdelasilla is about 6,000 years old, it poses a direct challenge to the idea that monumental burial traditions started in a single coastal region, such as in northwestern France, before spreading between maritime communities and eventually reaching inland areas. The findings suggest that inland communities were developing their own large monuments at the same time.

"Instead of having a single point of origin, the emergence of megalithism in Europe appears to follow a multiple model of interconnected regions involving not only the coast but also continental areas."