St Ibb's Church is located at the top of a hill in the churchyard. The oldest parts date back to the 13th century. It was enlarged in the early 1400s and vaulting was added later in the same century. The tower was damaged in wars between Sweden and Denmark and demolished in 1726. The font dates from the 13th century and is made of Norwegian stone. The altarpiece has been painted by Tobias Gemperlin before 1578 and donated by famous astronomer Tycho Brahe.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.