Underwater Stone-Age Wall Once Trapped Reindeer

For Holocene hunters in Germany, reindeer were a big menu item. But with tools like antler spearheads and atlatls still developing, they needed every trick they could find to bring down more game.

One group did it by creating a massive corral, researchers think. A German team using sonar recently discovered a Stone Age megastructure submerged below the Western Baltic Sea. It dates to about 11,000 years ago, spans 975 meters, and includes boulders weighing up to 11,000 kilograms.

Currently located in the Bay of Mecklenburg several kilometers off the coast of Rerik, Germany, it shows “pristine preservation” under about 20 meters of water.

Approximate location of the Blinkerwall. Image: Landesamt für innere Verwaltung Mecklenburg-Vorpommern via Wiki Commons


“The site represents one of the oldest documented man-made hunting structures on Earth, and ranges among the largest known Stone Age structures in Europe,” says the team’s paper in the journal PNAS.

Jacob Geerson, a marine geophysicist at Kiel University in Germany, led the landmark find. He told LiveScience that finding it at all was a surprise.

“It was a bit out of the blue,” Geersen said. “We did not look for the structure because we did not know it was there. But we resolved it on the seafloor from our multibeam echosounder data.”

AUV multibeam data from sections along the Blinkerwall. Images: Geersen et. al



From there, Geersen’s team applied archaeological diving techniques, including unmanned submersibles and SCUBA, to explore the structure. Now confident it’s human-built rather than naturally occurring, the team calls it the Blinkerwall.

The thousands of aligned stones are perched on a long-fluctuating coastline. The Bay of Mecklenburg doesn’t get deeper than 30 meters, and ephemeral drainage channels leading to the North Sea have consistently altered its characteristics.

The researchers think ancient hunters constructed it along a bog or lake to better contain their quarry. Reindeer were prevalent in the area until about 9,000 years ago.

The last time the structure was above sea level, the researchers think, was about 8,500 years ago. Continued investigation hopes to zero in on details of the Blinkerwall, including its precise age.

For now, it’s a promising new find in an area rife with terrestrial Stone Age relics. Northern Germany’s other early Holocene attractions include boggy hunting spots at the Saaler Bodden and Ahrensburger Tunneltal, plus well-studied campsites at Lake Schwerin, where archaeologists have found cremated bones.

The Blinkerwall stands as the region’s first underwater Stone Age discovery — and will likely lead to more like it, Geersen’s team said.

Sam Anderson

Sam Anderson spent his 20s as an adventure rock climber, scampering throughout the western U.S., Mexico, and Thailand to scope out prime stone and great stories. Life on the road gradually transformed into a seat behind the keyboard, where he acted as a founding writer of the AllGear Digital Newsroom and earned 1,500+ bylines in four years on topics from pro rock climbing to slingshots and scientific breakthroughs.