Aggersborg (Castle)

The precise dating of Aggersborg is complex, as an older settlement from the 9th and 10th centuries was located beneath the fortress. The castle itself, however, is attributed to the so-called Trelleborgs and was likely built around 980 under the reign of Svend Tveskæg. Its construction period is estimated at about two years, and its use lasted between five and twenty years. The complex was massive: the rampart, originally about 4 meters high and reinforced with oak wood, enclosed an area with a diameter of 240 meters. Inside, there were 48 longhouses, twelve arranged in each of four quarters, providing space for an estimated 5,000 men. Archaeological finds, including imported luxury goods such as rock crystal beads and a gold armlet, testify to the site's importance. The function of the fortress is debated: it could have been a trade center, a barracks, or a training camp for campaigns to England. A mention of a rebellion in 1086, during which Aggersborg was plundered, suggests possible use into the 11th century, although this is doubted by some researchers.

Aggersborg fortress is located in Aggersund, in the Vesthimmerland district, in the North Jutland region of Denmark. It is situated at an elevation of approximately 16 meters above sea level.

Today, the remains of Aggersborg fortress are accessible to visitors. The current, lower rampart was erected in 1990 to mark the original form of the complex and to make the dimensions of the once mighty Viking fortress tangible.

• Aalborghus Castle (Castle), approx. 41.1 km away
• Spøttrup Borg (Castle) (Castle), approx. 49.0 km away
• Fyrkat (Viking fortress) (Castle), approx. 52.1 km away
• Dronninglund Slot (Castle) (Castle), approx. 63.6 km away