Borve Castle, also known as Castle Wearie, is a ruined 14th century tower house. MacGibbon and Ross attributed the building of the tower to Amie mac Ruari, wife of John of Islay, and dated it to between 1344 and 1363. It was occupied by the Macdonalds of Benbecula until the early 17th century.
The ruined tower measures 18 metres by 11 metres, and 9 metres high. The walls are up to 2.7 metres thick. The entrance, in the south wall, led into the second of three storeys.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.