The Electoral Castle, with its solid construction and bulky tower, forms the townscape and portrays the power of its builder, the Archbishop and Elector of Trier. The castle had many purposes. It was a fortification to keep enemies out, a stronghold to keep the Boppard nobles at bay and a toll castle for collecting toll from the ships passing Boppard and filling the Elector’s pockets.
Like most castles along the Rhine, Boppard’s Alte Burg was often destroyed and experienced many changes throughout the centuries. The following all have found a home in the castle: customs office, the town gendarmerie, police station, courthouse, prison and military hospital. For the last hundred years it has also been home to the town’s museum with a large collection of Thonet furniture (since the 1970’s). Of special interest are the frescos in the former castle chapel dating 2nd half of the 14th century.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.