Definitions for safe area
Random House Webster's College Dictionary
an area near a combat zone that is maintained as being free from military attack.
The area of a television image that is expected to be viewable on all television screens, including old ones that typically crop the borders of the image.
Dictionary of Military and Associated Terms
A designated area in hostile territory that offers the evader or escapee a reasonable chance of avoiding capture and of surviving until he or she can be evacuated.