Why is the "Crooked Wall" crooked?
The constructors of the Danevirke strategically exploited the landscape by incorporating natural obstacles such as marshes and lakes. This stretch of the earthwork follows the curved course of a river’s floodplain, hence the name: Crooked Wall. It is ca.1300 years old. Much of the Danevirke east of here is strongly fortified by high banks. Further west the rampart flattens to a low dyke. Near Hollingstedt it is no longer visible. The reason for the difference is unknown.
The trade route linking the Viking-Age commercial centre of Hedeby with Hollingstedt ran to the north of the rampart. From Hollingstedt, travellers reached the North Sea via the Treene and Eider rivers. This is the shortest route between the seas. Archaeological evidence of the trade route and of a Viking Age settlement has been found just a few kilometres to the north near Ellingstedt. A wide ledge is visible along the base of the north slope of the Crooked Wall. Could this have been another track for patrolling the frontier?