Heers Castle built in the 13th century. Of its many owners, among the most notorious was Raes van Heers (1418–77), who was defeated and driven into exile by Charles the Bold at the Battle of Brustem in 1467. The castle, and the town of Heers, were laid waste by Charles's troops, although the castle was eventually repaired after Raes' death by his widow.
The family de Rivière d'Arschot lived here until the 18th century, when Barbara, daughter and heiress of the last Count, Henri de Rivière d'Arschot, became abbess of Herkenrode Abbey; on her death in 1744, the family became extinct.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.