Stonehenge, the prehistoric monument that has kept archaeologists and historians on a constant quest to unravel the mysteries surrounding it, served as a burial site approximately 5,000 years ago, a new radiocarbon study shows.

Archaeologists concluded that the site served as a monument dedicated to the dead longer than previously thought, from 3,000 BC until after the first stones were erected, 500 years later. The latest radiocarbon analysis of three cremated humans unearthed from Stonehenge in the 1950s indicated that the site had been intended from the very beginning as a place to put the remains of the dead.

The study is part of the Riverside Project, a seven-year archaeological investigation, supported by the National Geographic Society’s Committee for Research and Exploration and lead by Mike Parker Pearson of the University of Sheffield, England.

As Pearson pointed out, Stonehenge is no longer a “temporary” burial site, as previously assumed, but a burial site “from its beginning to its zenith.” Archaeologists estimated that a total of 240 people are buried here, most of them in the Aubrey Halls, a ring of 56 pits found at the site.

Given the fact that the number of burials was smaller in the early period and multiplied in time, archaeologists also assumed that this was in fact the burial site of a single elite family. One of the few artifacts found buried with the dead, a stone mace, comes to support this theory, as archaeologists assumed it may have been a symbol of authority.

Based on a previous discovery of a similar artifact, dating back to 2,000 BC and belonging to an important chief, archaeologists assumed that the mace at Stonehenge, which had an unusual head, belonged to a member of an elite family.

Furthermore, Stonehenge is believed to have been linked with a nearby timber monument at Durrington Walls, via the River Avon. The Durrington Walls monument measures approximately 500 m in diameter and some believe it was occupied by those who erected Stonehenge.

According to Pearson, the two monuments represented the realms of the living and of the dead, and while most of the dead were buried at Durrington Walls, it is assumed that only a “select few” were buried at Stonehenge.

Not everyone fully supports the theory that Stonehenge was a burial site from the beginning to the end. As Andrew Fitzpatrick of Wessex Archaeology, who did not participate to the study, told National Geographic, the material analyzed comes from very old excavations, which means scientists can’t be 100 percent sure where the material came from.

Despite the fact that one of Stonehenge’s purposes is now clear for some, there are still a lot of questions surrounding it that don’t have an answer yet, such as what construction techniques the builders used 5,000 years ago to create this massive monument.

There are a lot of theories regarding Stonehenge, and some scientists believe the monument to have connections with ancient astronomy; however the assumptions that it worked like a solar instrument have been rejected due to evidence indicating that it was not a visited site during the summer solstice, as expected, but rather during the winter.

Stonehenge and its surroundings is part of UNESCO’s World Heritage Sites list since 1986, and is a legally protected ancient monument.