A Solar Plea: The Mystery of Bornholm’s Engraved Sun Stones

Did a Volcanic Eruption Prompt Stone Age Rituals in Denmark?

Nearly 5,000 years ago, an island community in what is now Denmark faced a darkened sky and dwindling harvests. Archaeologists believe they turned to an extraordinary ritual¹, burying hundreds of engraved stones adorned with sun and plant motifs as an offering to restore balance.

Recent findings from Bornholm, a Danish island in the Baltic Sea, suggest these decorated stones—known as "sun stones"—may have been linked to a massive volcanic eruption. This environmental catastrophe likely caused a significant cooling period, devastating crops and disrupting communities. Researchers led by Rune Iversen from the University of Copenhagen have pieced together evidence that connects these enigmatic artifacts to a period of climate upheaval.

The Stones of Bornholm

Between 2013 and 2018, archaeologists excavated over 600 intricately carved stones from ritual sites on Bornholm. These sites, associated with the Funnel Beaker culture, were active around 2900 BCE. Many of the stones feature motifs of the sun and abstract patterns resembling plants or crops, hinting at their symbolic importance.

“It is a bit special that all of a sudden we have all these stones, and you don’t see them from before or later,” Iversen remarked.

The researchers believe the stones were deliberately buried in a coordinated effort. The ditches where the stones were found had been carefully filled, and circular wooden structures were built atop them, signaling the importance of the act.

More than 100 engraved stones unearthed in Denmark depict images of the sun. The stones, including the two shown here, may have been buried as part of a ritual to bring back the sun after a volcanic eruption, researchers say. John Lee/National Museum of Denmark, R. Iversen et al/Antiquity 2025