Beneath the waters of the Bay of Aarhus, Denmark, archaeologists have uncovered traces of a Stone Age settlement swallowed by the sea more than 8,500 years ago.
This summer, divers descended about eight meters (26 feet) near Denmark’s second-largest city and recovered animal bones, stone tools, arrowheads, a seal tooth, and a small piece of worked wood believed to have been a simple tool. The finds offer rare evidence of a coastal community that vanished as seas rose after the last Ice Age.
The excavation is part of a €13.2 million ($15.5 million) international research project funded by the European Union. The six-year initiative links experts from Aarhus University, the University of Bradford in the United Kingdom, and Germany’s Lower Saxony Institute for Historical Coastal Research.
Their aim is to map parts of the Baltic and North Seas, reveal submerged landscapes, and locate Mesolithic settlements as offshore wind farms and sea infrastructure expand.
Life by the water
Most Stone Age discoveries in Denmark have been made inland, far from the shoreline. Peter Moe Astrup, the underwater archaeologist leading the Danish excavations, said this site provides a direct window into life along the ancient coast.
“Here, we actually have an old coastline,” Astrup said. “We have a settlement that was positioned directly at the coastline. What we actually try to find out here is how was life at a coastal settlement.”
In the Bay of Aarhus, Denmark, divers are excavating an 8,500-year-old Stone Age settlement submerged by rising sea levels, part of a $15.5 million project aimed at unraveling the mysteries of ancient coastal life before it’s forever lost. pic.twitter.com/bhKZ5zr3Dk
— Nyra Kraal (@NyraKraal) August 26, 2025
Following the Ice Age, melting glaciers pushed sea levels upward. Around 8,500 years ago, the waters rose about two meters (6.5 feet) per century, Astrup noted, forcing hunter-gatherer groups further inland.
Astrup and his colleagues at the Moesgaard Museum in Højbjerg, near Aarhus, have excavated roughly 40 square meters (430 square feet) of the seabed. Using an underwater vacuum, they are sifting through the site meter by meter, searching for harpoons, fishhooks, or remnants of fishing structures.
A time capsule beneath the sea
Astrup described the settlement as “a time capsule” where organic material has remained sealed in an oxygen-free environment since the sea advanced. “We find completely well-preserved wood,” he said. “We find hazelnut. … Everything is well preserved.”
Excavations in Aarhus Bay and off Germany’s coast mark the early stages of the project. Later phases will target two sites in the harsher waters of the North Sea, where a vast landmass known as Doggerland once connected Britain with continental Europe before it disappeared beneath rising seas.
Tracing the waters’ rise
To reconstruct how fast seas advanced, researchers are using dendrochronology, or tree-ring dating. Submerged stumps preserved in seabed mud reveal when coastal forests were drowned.
“We can say very precisely when these trees died at the coastlines,” said Jonas Ogdal Jensen, a dendrochronologist at the Moesgaard Museum. “That tells us something about how the sea level changed through time.”
Lessons for today
Researchers say the work not only illuminates the past but also resonates with present-day challenges. “It’s hard to answer exactly what it meant to people,” Astrup said. “But it clearly had a huge impact in the long run because it completely changed the landscape.”
Global sea levels rose by an average of 4.3 centimeters (1.7 inches) in the decade up to 2023. For scientists in Denmark, the submerged settlement is a reminder that human societies have faced — and adapted to — rising seas before.
