Isegran Fortress Ruins

Isegran is the first place in Fredrikstad mentioned in history. The Earl of Borgarsyssel, Alv Erlingsson, also called MindreAlv, had a small fortress on Isegran in the late 1200s. In the 1670s, the island was fortified with a large battery platform, Isegran tower, and later a small fort was built to protect the river. Until 1685 Isegran was the royal shipyard for the danish-norwegian fleet and during the Great Northern War, the island was the naval base for Peter Wessel Tordenskiold. The historic island can be reached via the Kråkerøy bridge or with the city ferry.

Address
Mindre-alvs vei 1, Fredrikstad, Norway

Established
13th century