Akershus Fortress or Akershus Castle is a medieval castle that was built to protect Oslo, the capital of Norway.
It has also been used as a prison. The first construction on the castle started around the late 1290s, by King Haakon V, replacing Tønsberg as one of the two most important Norwegian castles of the period (the other being Båhus). It was constructed in response to the Norwegian nobleman, Earl Alv Erlingsson of Sarpsborg’s earlier attack on Oslo.
Current use
After the main building has undergone restoration, it has been used for official events and dinners for dignitaries and foreign heads of state.
Akershus fortress is still a military area, but is open to the public daily until 21:00. In addition to the castle, the Norwegian Armed Forces Museum and Norway's Resistance Museum can be visited there. The Norwegian Ministry of Defence and Defence Staff Norway (armed forces headquarters) have a joint modern headquarters in the eastern part of Akershus Fortress.
Norwegian Royalty have been buried in the Royal Mausoleum in the castle. They include King Sigurd I, King Haakon V, Queen Eufemia, King Haakon VII, Queen Maud, King Olav V and Crown Princess Märtha.