When archaeologists uncovered four ancient ring-shaped fortresses in Denmark in the 1930s, the find profoundly changed the way they thought about the Vikings that built them. Rather than mindless marauders, Vikings in the Middle Ages must have been a complex, technologically advanced people to build these fortifications. Now, Danish archaeologists have described a fifth ring fortress—the first such discovery in more than 60 years—revealing even more about these architecturally gifted warriors.
The new fortress, called Borgring, was found principally using an aerial, laser-based surveillance method called LIDAR, which returns an extremely high-resolution 3D ground map. It’s located on the Danish island Zealand, south of Copenhagen.