architecture
blue sky
bunker
concrete
fortification
fortified
frame
framed
german
great
green
gun slot window
hidden
hills
historic
hole
landmark
leaves
military
mountain range
mountain view
mountainous
nature
old
outpost
panorama
pillbox
ruins
scenery
second
second world war
secret
slovenia
stone
two
view
war
woodland
world
world war
world war ii
ww2