The fortress, perched with a magnificent sentinel's view over Oslo's fjord, offers plenty of attractions for visitors.
For 700 years it has watched over Oslo, first as a medieval castle, then as a Renaissance palace. Now most of its facilities are open to the public, and it is a favorite with tourists and residents.
The fortress and its grounds house the Home Front Museum, documenting Norway's resistance movement during the years of German Occupation (1940-45) during WWII. The museum is housed near the spot where Norwegian patriots were executed during the war.
The Defense Museum is part of the fortress, and displays Norwegian military history from the Viking Age up to the present time.
There is also the royal burial chapel, taken into use when Queen Maud died in 1938, and which was the original palace chapel from the 1580s.
The Prison Museum is in the Crown Prince's powder magazine. This area was used as a prison around 1830 and was where Norway's notorious master thief Ole Høiland was held.
Akershus Fortress is not just steeped in history, it is still in use as a site for official government receptions.
The Akershus Fortress Foundation for Art and Culture (SAKK) stages historical plays, tours, seminars and concerts.