The Marinen is an old defense facility at Nidelva in Trondheim. Today, the area is a recreation area for the city’s population. Together with General von Hüth’s bastion and Bastion Prins Carl, the navy formed a defense facility that was supposed to protect the city against enemy naval vessels. The facility is located between Nidaros Cathedral and the Archbishop’s Palace on one side, and the Nidelva River on the other and stretched all the way from Gamle Bybro to Elgeseter bridge.

The area where today’s buildings stand was originally part of the defense system of bastions and palisades on the Nidelven. At the beginning of the 19th century, they got a new and expanded function. The defenses around Trondheim were originally built to protect against attacks from the east. The British attacks on Copenhagen in 1801 and 1807 demonstrated the potential of enemy naval vessels. Against this background, the navy and the coastal forts were given a greater place. A storage area was established for the flotilla and a shipyard for the construction and maintenance of vessels at the Navy.

The facility had large dimensions with buildings along the Nidelven all the way to the Elgesæter bridge. But large parts of the facility have been lost to fire or demolition. Today, only six buildings remain. The last remaining sheds for gun sloops were demolished in the 1960s. The area is currently used as a recreation area for the city’s population.