In Stensätter is one of Sweden's three northernmost ancient forts.
The castle is by far the best preserved from this time period. The mountain falls steeply on three sides. Only the hillside to the southeast can be climbed on foot. On each side of the opening is larger stone mounds disordered. This has been interpreted as if there has been any "towers" with a wooden door, to protect the entrance. The defensive wall consists of two arms. To the south, with a shorter higher, which soon reaches the precipice and to the north an approximately 150 m long section, which goes against a part which is located higher of the mountain. This part of the wall is in some places approximately 3 meters wide at the base. Outside the main wall you can see the remains of another wall of stone. In the forest area just below the wall it has been discovered a pile of rocks (tomb), which has been dated to at least the Viking period 800-1050 AD.