Five Danish fortresses have just been added to the UN organization UNESCO’s list of world heritage sites: They are Aggersborg (Limfjorden), Borgring (Køge), Fyrkat (Hobro), Nonnebakken (Odense), and Trelleborg (Slagelse).
- These archaeological sites comprise a system of monumental ring-shaped Viking-Age fortresses sharing a uniform geometric design. Constructed between about 970 and 980 CE, the fortresses were positioned strategically near important land and sea routes, and each made use of the natural topography of their surrounding landscape for defensive purposes.