blockhouse and chinese flag on the rock, srgb image

abandoned activity amoy architecture army blockhouse building bunker camouflage camouflaged cement chinese combat concept concrete conflict construction countryside cover danger decay defending defense destruction extreme fence fight five flag forest fort fortification fortifications fortified fortress guard historic historical history hole landscape line loophole mask military nature outdoors outside paint park pill pillbox play power protection red rock ruin safe safety shadow shelter shooter shot soldier star stone strength structure survival target visor warfare wartime weapon wood