barbed perimeter fence

access alert army authority authorization background barb barbed barrier beware blade border boundary burn burning capture cloud coil coiled containment cut danger dangerous deadly defense divide enemy explode explosion farm farming fence fencing fire flame fort freedom hate headquarters helical helix horizon horizontal injure iron keepout limit metal obstruct obstruction outdoors perimeter prison prohibit razor razorwire restrict rotate rounded rusted rustic rusty secure security sharp sky slice smoke stop storm trespass ups war windy wire wired yellow zone