Bohus Fortress
Kungälv Municipality, Sweden · built 1308
Bohus Fortress lies in Kungälv, Bohuslän, Sweden, north east from Hisingen where the Göta river splits into two branches (20 km (12 mi) north of Gothenburg). It commands the surrounding area from a cliff 40 m (130 ft) high, with the river forming a natural moat around it. The fortress used to be situated along the old Norwegian–Swedish border.
Fort data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).