Group Fortification Yser
France · built 1907
The Feste Prinz Regent Luitpold, renamed Group Fortification Yser after 1919, is a military installation near Metz. It is part of the second fortified belt of forts of Metz and had its baptism of fire in late 1944, when the Battle of Metz occurred.
Fort data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).