Dannewerk

The Dannewerk (Danish: Dannevirke, German: Danewerk) is a system of Danish fortifications in Schleswig-Holstein, Germany. It stretches for approximately 30 kilometers (19 miles) from the Baltic Sea coast near Schleswig to the wetlands west of Schleswig. It served as a crucial defensive line during the Viking Age and the Middle Ages, protecting Denmark (and the Danish-dominated southern Jutland) from incursions from the south, primarily by the Franks, Saxons, and later the Holy Roman Empire.

The Dannewerk consists of several walls, ditches, and ramparts constructed and modified over centuries. The earliest structures date back to the Viking Age, with continuous additions and reinforcements made until the 19th century. The primary materials used in its construction were earth, timber, and stone.

Throughout its history, the Dannewerk played a significant role in numerous conflicts, including wars between Denmark and the Holy Roman Empire, as well as the Schleswig Wars of the 19th century. While strategically important, the Dannewerk was not always successful in halting invading armies due to its length, the evolving nature of warfare, and sometimes inadequate manning.

Today, portions of the Dannewerk remain visible as historical earthworks and are a protected archaeological site. Some sections have been reconstructed or preserved to allow visitors to appreciate the scale and significance of this ancient fortification. The Dannewerk is considered an important cultural heritage site in both Denmark and Germany.