Overview
- The structure was first spotted on a laser-mapped seabed chart by geologist Yves Fouquet and then verified in about 60 dives.
- It lies roughly nine meters below present sea level, having been built when local shorelines were significantly lower.
- Dating places the construction in the Mesolithic–early Neolithic transition, suggesting organized labor and technical skill.
- Its purpose remains unresolved, with hypotheses including a seawall, a fish trap, or a hunting trap.
- The findings, described as unique in France for the period and older than Brittany's menhirs and dolmens, were published in the International Journal of Nautical Archaeology.