The Danevirke is one of northern Europe's great frontier landscapes, a chain of ancient defensive earthworks across the base of the Jutland peninsula. For centuries it marked a strategic and symbolic boundary, tied closely to Danish history even though it now lies in Germany.
The museum and surviving ramparts make the site much easier to understand than a line on a map. Walk a section if you can: the low banks, fields, and borderland setting say a great deal about how geography shaped politics in this part of Schleswig.