Bohus Fortress (also known as Baahus or Båhus, originally: Bagahus) lies along the old Norwegian–Swedish border 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.