The Viking Ship Museum (Vikingeskibsmuseet) is the Danish national museum for ships, seafaring and boatbuilding in the prehistoric and medieval period.
Around the year 1070, five Viking ships were deliberately sunk at Skuldelev in Roskilde Fjord in order to block the most important fairway and to protect Roskilde from enemy attack from the sea. These ships, later known as the Skuldelev ships, were excavated in 1962. They turned out to be five different types of ships ranging from cargo ships to ships of war.
The Viking Ship Museum overlooks Roskilde Fjord and was built in 1969 especially to exhibit the five newly-discovered ships. In the late 1990s excavations for an expansion of the museum uncovered a further 9 ships including the longest Viking warship ever discovered, at 36 metres.
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.