For Danes, the Danevirke is more than an archaeological site, because over the centuries it grew into a symbol. In the nineteenth century, when national feeling was rising across Europe, the Danes saw the old wall as the guardian of their southern border and of their identity, and the name was given to songs, newspapers and political societies. The idea that the true frontier lay at the Eider river, not at the present border, drove a bitter struggle between Danish and German nationalists, a conflict that ended in war and in the loss of the duchies in 1864.
The sections labelled Crooked Wall Areas 1 to 2 and the Main Wall form the heart of the system. The Main Wall, with its ditch and bank, is the part that most people picture when they think of the Danevirke, and it has the strong, simple lines of something built to a plan. It was raised in the tenth century, according to tree-ring dates, probably under King Harald Bluetooth, and was heightened and faced over the following centuries. After the First World War, plebiscites in 1920 finally drew a new frontier, further north, which still runs between Germany and Denmark today.
The ride here runs across the flat farmland near Groß Rheide, among fields of grain and maize, and the roads are small and quiet, with the odd gentle bend and a little tractor traffic. The surfaces are good, and the villages are tidy and well kept. The land is open to the wind, and the sky seems very big. On a clear day, you can see the church towers of several villages at once.
Kropp, six kilometres away, has the fuel and the shops, and Dannewerk and Schuby have little more than a bakery and a pub. Bring something to drink, and a jacket against the wind. Walk a short way along the bank and stand on top. You can feel the weight of the history, and the plain good sense of the people who chose the spot. It is a very peaceful place for such a contested one.