Image Credit: S.moeller, via Wikimedia Commons

Ancient Stone Wall Found Beneath the Sea off France Coast

Marine archaeologists have uncovered a massive stone wall submerged off the coast of Brittany in western France, dating back to around 5,800 BC, making it one of the oldest known large-scale underwater structures in Europe.
The wall, stretching approximately 120 meters in length and now lying about nine meters below sea level, was originally built along the ancient shoreline of what is today the Île de Sein. At the time of its construction, the structure would have stood between high and low tide zones, before rising sea levels gradually submerged the area.
Archaeologists believe the wall may have served as a fish trap or as a protective barrier against encroaching seawater. The structure is around 20 meters wide and two meters high, and includes large upright granite stones arranged in parallel lines, around which smaller stones were carefully packed. These standing stones may once have supported wooden nets or barriers used to capture fish as tides receded.
With an estimated weight of more than 3,000 tonnes, the construction suggests the presence of a well-organized and settled prehistoric community capable of large-scale cooperative labor. Researchers note that the techniques used resemble later Neolithic stone traditions, raising the possibility of shared knowledge between Mesolithic hunter-gatherers and early farming societies.
The discovery was made using modern seabed mapping technologies, and subsequent dives allowed archaeologists to document the structure in detail. Researchers suggest that such submerged sites may have inspired local legends of sunken cities, reflecting collective memories of landscapes lost to rising seas thousands of years ago.

Published on: 12-12-2025

Edited by: Abdulmnam Samakie

Source: BBC