What is "aggersborg"

Aggersborg is the largest of Denmark's former Viking ring castles, and one of the largest archeological sites in Denmark. It is located near Aggersund on the north side of the Limfjord. It consists of a circular rampart surrounded by a ditch. Four main roads arranged in a cross connects the castle centre with the outer ring. The roads were tunnelled under the outer rampart, leaving the circular structure intact.

The ring castle had an inner diameter of 240 metres. The ditch was located eight metres outside of the rampart, and was approximately 1.3 metres deep. The wall is believed to have been four metres tall. The rampart was constructed of soil and turf, reinforced and clad with oak wood. The rampart formed the basis for a wooden parapet. Smaller streets were located within the four main sections of the fortress.

The modern Aggersborg is a reconstruction created in the 1990s. It is lower than the original fortress.