footbridge at charlemont fortress, ditch with stagnant water with blooming algae

ancient aqueduct arch architecture ardennes bastion battle border building bunker castle citadel countryside defence ditch entrance europe exterior forces fort fortification fortified fortress french green heritage hill hillside historic history landmark medieval moat monument mountain old path rock ruins stone stones structure tourism tourist tourists travel view wall war footbridge charlemont stagnant water blooming algae brick walls covered wild vegetation sunny summer day blue sky givet department france