The area is connected to mainland Horten via an old canal system constructed between 1854 and 1863.
Karljohansvern was known as 'Horten Military Shipyard' and was the first location in Norway to have electricity, thanks to its own power plant.
It is home to one of the world's most significant photography museums, the Preus Museum, housed in a converted boiler house.
The base was named after King Carl Johan, who personally chose the location for the naval base due to its strategic defensive position.
The site includes the oldest surviving iron-hulled warship in Norway, the 'Statsraad Lehmkuhl' predecessor, docked nearby.
Many of the original workshops and factory buildings from the 1850s are still standing and currently repurposed for businesses and cultural use.
Karljohansvern is a former main naval base of the Royal Norwegian Navy, situated on a group of islands connected to the mainland of Horten. Established in 1818, it served as the nation's primary naval shipyard and maritime defense center for over 150 years. The site is now a heritage area managed by Forsvarsbygg, preserving unique 19th-century military architecture, dry docks, and canal systems. The area functions as a civilian park and cultural hub while maintaining its historical naval identity. It features a high concentration of protected buildings, including the old maritime workshops and the commander's residence. The surrounding landscape consists of recreational woodland, shoreline paths, and historical fortifications. It is the site of the Preus Museum, which focuses on photography and camera history.
The red-brick canal bridges overlooking the water with the historic naval workshops in the background.
Walk the perimeter trail along the water for views of the surrounding archipelago.
Combine your walk with a visit to the Preus Museum to understand the intersection of technology and history.
Check the local event calendar, as the area frequently hosts festivals and open-air concerts.
Do not attempt to enter buildings marked as private offices or restricted industrial zones, as many historic structures are now privately owned.
Outdoor park areas are accessible year-round; museums within the complex follow individual seasonal operating patterns.
