Adelsnäs (formerly known as Näs) manor was named after Johan Adelswärd, who acquired the local copper mine in 1781. The present manor building was built Theodor Adelswärd in 1916-1920. English garden and parks around the Bysjön lake are popular when open to the public.
The unique detail is a “Sun Cannon”, which is installed in a red brick tower from 1853. It is a 6-pound cannon from the same period with an ignition system consisting of a magnifying glass mounted on a movable arm, adjustable to the sun’s different meridian latitudes. At exactly 1 pm, when the sun reaches its highest point at midday in summertime, the sun shines through this opening, hitting the magnifying glass focused on the priming compound at the back of the cannon.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.