The Hindenburg Line was a German defensive position of World War I, built during the winter of 1916–1917 on the Western Front.
Batterie Pommern, also referred to as the 'Long Max', is a naval artillery situated in Koekelare, Belgium.
Ouvrage Chesnois is a lesser-known fortification nestled in the wooded hills of northeastern France.
The forts of Verdun comprise an intricate network of defensive structures.
The Fortified Position of Liège is a group of twelve forts built around the city of Liège.
The Line of Du Moulin, a fortified defense line, is situated within Maastricht.