abandoned
barbed
border
boundary
california
customs
danger
dangerous
derelict
desert
deserted
dry
edge
empty
end
eu
europe
fence
forsaken
frontier
grass
green
hazard
hazardous
high
horizon
law
mexico
ocean
place
plant
quarantine
razor
refugee
regulation
rule
sea
sicily
sky
skyline
state
syria
texas
usa
wall
water
wild
wire
yellow
zone