abstract
background
barb
barbed
barbwire
barrier
black
border
boundary
chain
close
closeup
crime
danger
dangerous
design
detail
enclosure
fence
forbidden
freedom
guard
hard
industrial
iron
isolated
jail
jesus
metal
metallic
military
nobody
old
pattern
prison
protection
razor
rusty
safety
security
shape
sharp
steel
symbol
thorn
thorns
war
white
wire