Every year at the winter solstice, people gather at Newgrange, an ancient Irish round tomb that dates back to the Stone Age, to watch the first sunrise of winter stream through an opening in the site’s ancient stones. Now, the significance of the site is being questioned by archaeologist Michael Gibbons, who writes in a new paper that the act of “trapping” the sun at the site might not be a 5,000-year-old practice at all, but instead, a 50-year-old “construct,” reports the Irish Times.

Gibbons co-authored a paper published in the journal Emania. The researchers argue that the site’s famous “roof box” used to filter light down and illuminate the historic structure was not an original feature of Newgrange, but instead was created during site excavation and renovation half a century ago.

The way it works, on days with clear skies between December 19 and 23 each year, a beam of light filters through the “roof box” at the top of the ancient structure, filling the site’s inner chamber with light for more than 17 minutes. This has been described as marker for the beginning of new life at the start of a new year.

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Like Stonehenge in England, the site attracts crowds wanting to experience a mystical moment at solstice every year.

But in his research, Gibbons suggests that Newgrange’s moment in the sun is something of a historic hoax — not part of ancient ritual, but a more modern invention courtesy of the late Michael O’Kelly, who led the 1960s excavation of the site.

Gibbons said that O’Kelly’s assertions that the ancient tomb remained mostly unchanged from the Neolithic period are inaccurate and that Iron Age-era people at the site might have made adjustments to the tomb’s overall profile. More pointedly, Gibbons said that the “roof box” does not have “a shred of authenticity” and that it was “fabricated” during O’Kelly’s reconstruction, the Irish Times reports.

This current research isn’t the first to take issue with the authenticity of the site. Back in 2006, Newgrange made the dubious honor of being included in a list of “world’s worst archaeological reconstructions” by Durham University.

Gibbons’s critiques remain somewhat controversial. Dr. Richard Hensey, author of “First Light: The Origins of Newgrange,” told the paper that it is “not correct” to call the “roof box” a “construct.” He asserted that other studies have indicated the structure is 5,000 years old.