While the oldest parts of Havdhem Church have been identified as being from the first half of the 12th century, graves dating from the period of the arrival of Christendom to Gotland (11th century) have been discovered in the cemetery. The choir is the oldest part of the church itself. It shows resemblances with the churches of Garde and Källunge. The choir portal is however later, from the 13th century. The nave dates from circa 1200 but was originally both lower and somewhat shorter. It was possibly enlarged in 1580, following a fire that devastated the church. The apse was added to the choir at approximately the same time as the nave was built. It displays similarities with a now ruined church in Visby, St. Drotten. The church tower dates from the middle of the 13th century and was originally slightly higher. It replaced an earlier, smaller tower.
Internally, the apse retains a few fragments of frescos displaying Byzantine influences. The altarpiece dates from 1667 and the pulpit from 1679, while the baptismal font is from 1685. The triumphal cross is a work from the 15th 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.