Ragnhildsholmen Medieval Fort Ruin

Went out to find good spots for photo sessions, and this medieval fort ruin, called Ragnhildsholmen, was great.     https://youtu.be/1syfMvqEklo   Ragnhildsholmen belong to Norway around 1250's when it was built. Sweden won over the whole region in 1658 in The Roskilde Peace Treaty negotiations. This fort however, was only in use for about hundred years as its significance ...