background
bar
barb
barbed
barbed wire
behind
border
boundary
cage
caged
chain
close
clutching
container
crate
crime
criminal
curiosity
desirous
dirty
escape
fence
fish
forbidden
freedom
gate
grid
guard
holding
iron
law
lock
locked
loneliness
lonely
marine life
mesh
metal
net
nobody
outdoors
sad
safety
secure
security
shelter
steel
third world
wild life
wire