Cocev Kamen is a hilltop cave site of volcanic origin near the town of Kratovo. Objects (bone fossils) discovered near the cave suggest human presence since the Paleolithic. Authors agree that the site served as a gathering point for sacrificial rituals from the Neolithic, during the Bronze Age, throughout antiquity until the Middle Ages as clarified by an abundance of pottery shards, stone (flint) tools and bone fragments unearthed from the surrounding areas. Several caves and rock shelters are decorated with red figurative art work. Comparison with similar sites in Bulgaria and Italy suggests that the paintings are indeed prehistoric.
Debated remains the notion that Cocev Kamen has also been used as an (astronomical) observatory.
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.