Circular rampart of Burg — Wikipedia

The circular rampart of Burg (German: Ringwall von Burg) is a defensive work from the Early Middle Ages period located near the German town of Celle in Lower Saxony. The site, dating roughly to the 10th century and located in an inaccessible area of marsh by the River Fuhse, probably acted as a refuge for the local population (against Viking or Slav attacks). Today this 3-metre-high (9.8 ft) circular embankment belongs to one of the most important Early Middle Age historical monuments in Celle.