What Fortress used as a palace and prison has the Festning tunnel running underneath it?
Akershus Fortress Akershus Fortress (Norwegian: "Akershus Festning" ) or Akershus Castle (Norwegian: "Akershus slott" ) is a medieval castle that was built to protect Oslo, the capital of Norway. It has also been used as a palace and as a prison.
Hofburg, Innsbruck The Hofburg (English: Imperial Palace ) is a former Habsburg palace in Innsbruck, Austria, and considered one of the three most significant cultural buildings in the country, along with the Hofburg Palace and Schönbrunn Palace in Vienna. The Hofburg is the main building of a large residential complex once used by the Habsburgs that still includes the Noblewomen's Collegiate Foundation, the Silver Chapel, the Hofkirche containing Emperor Maximilian's cenotaph and the "Schwarzen Mandern", the Theological University, the Tyrolean Folk Art Museum, Innsbruck Cathedral, the Congress, and the Hofgarten (Court Garden).