It is unknown when Schuttbourg Castle was built, although some sources say it dates back to the 12th century. It was first mentioned in the 15th century. It was the possession of the Lords of Fischbach who later sold it to the Lords of Clerf.
In the beginning of the 20th century it was a ruin. In 1936 it became private property and was rebuilt into a youth hostel, which opened in 1939. In the Second World War the castle was damaged severely during the Ardennes Offensive. In 1950 these damages were repaired.
The castle is now still private property.References:
Kristiansten Fortress was built to protect the city against attack from the east. Construction was finished in 1685. General Johan Caspar von Cicignon, who was chief inspector of kuks fortifications, was responsible for the new town plan of Trondheim after the great fire of 18 April 1681. He also made the plans for the construction of Kristiansten Fortress.
The fortress was built during the period from 1682 to 1684 and strengthened to a complete defence fortification in 1691 by building an advanced post Kristiandsands bastion in the east and in 1695 with the now vanished Møllenberg skanse by the river Nidelven. These fortifications were encircled by a continuous palisade and thereby connected to the fortified city. In 1750 the fortress was modernized with new bastions and casemates to protect against mortar artillery.