Kristiansten Festning

General Johan Caspar von Cicignon, chief inspector of Norwegian fortifications, was together with Anthony Coucheron responsible for rebuilding the city after the great fire of April 18th 1681. In the new town plans for Trondheim he drew a fortress at a strategic position overlooking the city, where it could fight off future invasions. The foundation was laid in 1682, and the fortress was built over the course of the next three years. The fortress was built at hilltop in an area called Bakklandet, from where the Swedes had previously controlled the city twice, in 1564 and 1658.

The fortification was originally meant to be a symmetrical shaped star around the dungeon, but was custom-built to fit the uneven terrain in an irregular star shape with nine points. The area around the fortress housed a number of buildings connected to it, but over the course of the years they have all been demolished, leaving only the fortress itself and the commandant's building left. The fortress was reconstructed in 1740 to the shape it has today.

Around the fortification there are dikes housing casemates and arched residences and storage facilities, which was used for living quarters for the crew, kitchen, prison and storage. The casemates are preserved well, and are still being used today for various purposes.

In 1816 Karl III Johan decided that the fortress was to be demolished, but it was saved when it was decided that the canons would be used to alert the city's residents in case a fire broke out. The commandant's building was raised after the fortress closed, in the 1820's. The only time the fortress was used in war was during the Great Nordic War (1700-1721). Before that only a few soldiers were stationed at Kristiansten.

The fortress underwent extensive renovation in 1997, in connection with the city's 1000-year anniversery. Flood lighting was installed, and one of the casemates was made into a chapel. The commandant's building was renovated and turned into a restaurant. The fortress is considered a museum, and is open to the public for free, wednesday through sunday.