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.
Sinop Fortress Prison Sinop Fortress Prison, (Turkish: "Sinop Kale Cezaevi" ) was a state prison situated in the inside of the Sinop Fortress in Sinop, Turkey. As one of the oldest prisons of Turkey, it was established in 1887 within the inner fortress of the centuries-old fortification located on the northwestern part of Cape Sinop. The prison was closed down in 1997 and the inmates were transferred to a modern prison newly built in Sinop.