Akershus Fortress has stood on its rocky promontory above Oslo's harbour since around 1300, when King Håkon V decided that a strategic headland called Akersneset needed a proper castle. In over 700 years it has survived sieges, served as a royal residence, and hosted Norway's most feared prison. It has never fallen to a hostile force.

In the 1600s, the medieval castle was rebuilt as a Renaissance fortress with bastions, giving it the layered silhouette visible today. During the Second World War, the Germans used it as a headquarters and prison camp, and the Norwegian Home Front Museum now occupies part of the complex.

VoiceMap's self-guided audio tours trace the fortress's long arc from medieval royal seat to wartime occupation site, placing the castle within Oslo's evolving waterfront and connecting it to Norway's experience of German rule, resistance, and liberation.