The Vichtenstein castle sits above the Danube valley opposite to the market municipality of Upper Cell (Lower Bavaria). The castle is in the centre of the municipality Vichtenstein. There is no documentary for the construction of the castle but it is believed to have been started around the year 1100. The castle was an administrative centre of the Bishopric of Passau and in the 14th century it was mortgaged several times until it became the property of the counts of Schauberg.
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.