Feste Prinz Regent Luitpold/Group Fortification Yser - Credit: Wikimedia Commons
The , 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. Read more on Wikipedia
Source: en.wikipedia.org