The Groß Raden Archaeological Open Air Museum is in a depression that borders directly onto the lake of Groß Radener See. On a peninsula in front of that lies its circular castle rampart, visible from afar, which has a diameter of 50 metres. From 1973 to 1980 extensive excavations were carried out here, led by Ewald Schuldt, during the course of which the remnants of a Slavic settlement dating to the 9th and 10th centuries was unearthed. The fort has been reconstructed based on the excavations and established as an archaeological open-air museum. It has been enhanced by finds from the Slavic castle of Behren-Lübchin.
References:The Gravensteen is a castle in Ghent originating from the Middle Ages. The name means 'castle of the counts' in Dutch. Arnulf I (918–965), Count of Flanders, was the first to fortify this place, building a medieval bastion on this high sand dune, naturally protected by the river Leie and its marshy banks. This bastion consisted of a central wooden building and several surrounding buildings, also in wood.
In the early 11th century, the wooden building was replaced by a stone residence, consisting of three large halls that made up three storeys, connected by a stone stairwell. The monumental stone staircase, the light openings, the fireplaces built into the walls and the latrines were signs of considerable luxury and comfort in those days. There was probably also a tower.