Poland, Oswiecim: Auschwitz concentration camp prisoner barracks with barbed wire fence in the foreground.

Close up of barbed wire (razor wire) fence along a border.

Berkshire, England: Sign on fence 'this is a prohibited place within meaning of official secrets act' Rolled barbed wire and CCTV camera at perimeter of nuclear weapons factory.

Poland, Oswiecim: Barbed wire fence in front of of guards tower at Auschwitz concentration camp. Pull focus to show close up of three strands of barbed wire.

Nevada, USA: No trespassing sign at factory fence