The walls of the ancient Fishermen's Chapel are reputed to date from the middle of the 6th century, but some authorities give a later date. It is however only a few monastic chapels survived the destruction of over fifty others at the hands of the Reformers in the 16th century. The material used in the chapel is the same as was used in the parish church: limpet shells crushed and dissolved with boiling sea-water. The stone roof was raised in the 14th century. The monks of that period evidently found the roof too low and squat for wall paintings. These were discovered in 1918. After a severe storm, colour was revealed on the ceiling and a picture of the 'Assumption' was seen, but in a damaged condition. But underneath the plaster was found another painting, 'The Annunciation', of about 1310-1315 A.D. At the foot of this painting are seen fourteen figures, supposedly members of an old Jersey family, the head of which had paid for this painting.The floor was restored to its earlier level in the 1980s to the medieval level, and the 'low, squat' aspect of the chapel which appears in early photographs is now gone, as the proper proportions can be seen.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.