Danevirke

The Danevirke is a system of Danish fortifications in Schleswig-Holstein, Germany. This historically important linear defensive earthwork across the neck of the Cimbrian peninsula was initiated by the Danes in the Nordic Iron Age at some point before 500 AD. It was later expanded multiple times during Denmark's Viking Age. The Danevirke was last used for military purposes in 1864 during the Second War of Schleswig.

The Danevirke consists of several walls, trenches and the Schlei Barrier. The walls stretch for 30 km, from the former Viking trade centre of Hedeby near Schleswig on the Baltic Sea coast in the east to the extensive marshlands in the west of the peninsula. One of the walls, between the Schlei and Eckernförde inlets, defended the Schwansen peninsula.