New Study Finds Carnac Stones May Be Europe’s Oldest Megalithic Site!
A recent archaeological breakthrough has shed new light on one of Europe’s most mysterious prehistoric landscapes, the iconic Carnac stone alignments in Brittany, France. Thanks to cutting-edge research led by Dr Bettina Schulz Paulsson from the University of Gothenburg, these ancient stones are now believed to date back as far as 4600 BCE, making them possibly the oldest known megalithic structures in Europe.
This discovery comes from a collaborative effort between French and Swedish researchers as part of the NEOSEA project, funded by the European Research Council. Their focus? A lesser-known section of the Carnac complex called Le Plasker, located in Plouharnel.
Photo Credit: Snjeschok / CC BY-SA 3.0
If you’ve ever visited Brittany, you might have seen the stunning rows of standing stones stretching across the landscape near Carnac. Over 3,000 of them, laid out in long lines or sweeping curves, span nearly 10 kilometres along the coast between Carnac and Erdeven. Unlike Stonehenge’s familiar circles, these stones form more linear patterns, and they've puzzled archaeologists for centuries.
Now, excavations at Le Plasker are offering long-awaited answers. Carried out by teams from the University of Gothenburg, the University of Nantes, and French excavation firm Archeodunum, the project included radiocarbon dating of nearly 50 samples taken during rescue digs. With the help of Bayesian statistical modelling, the team achieved an incredibly precise timeline for when these stones were put in place.
The findings suggest the stone alignments were erected between 4600 and 4300 BCE. That’s earlier than the stone circles in the British Isles, placing the Bay of Morbihan, where Carnac is located, at the very origins of Europe’s megalithic tradition.
Even more fascinating, the archaeologists found remnants of fire pits and hearths alongside the stones. While their exact purpose remains unknown, it hints at possible communal or ritual activities, perhaps feasts or ceremonies, tied to the creation of these monuments.
Photo Credit: Blanchard et al., Antiquity (2025)
The surprises didn’t stop there. Beneath the megalithic layers, researchers discovered a monumental tomb dating to around 4720 BCE, built on top of a Mesolithic hunter-gatherer dwelling. This find could represent one of the earliest examples of large-scale funerary architecture in north-western France, suggesting a transition from nomadic to more settled, ceremonial ways of life.
Although many of the original stones have been lost over time, the foundation pits where they once stood remain. These reveal a consistent alignment, north-northwest to south-southeast, across different periods, hinting at an intentional and symbolic layout that likely held deep meaning for the people who created it.
Despite all these new insights, the ultimate purpose of the Carnac alignments still isn’t fully understood. Were they boundary markers? Processional pathways? Calendrical tools aligned with celestial events? We may never know for certain, but what is clear is that this landscape was a focal point of activity, meaning, and memory for prehistoric communities.
The discovery and dating of Le Plasker doesn’t just push back the timeline of megalithic building, it repositions the Carnac region as a cultural hub at the dawn of Europe’s monumental age. From these early stones, a tradition would spread across the continent, shaping the sacred landscapes of Neolithic Europe.