Fort Schoenenbourg is one of the impressive Gros Ouvrages of the Maginot Line. It is located topwards the east end of the Alsace section of the line.
It comprises six combat blocks and separate personnel and ammunition entrances, all connedcted with over 3,000 metres of underground passages, up to 30 metres beneath the surface. It was heavily attacked at the beginning of World War II but remained largely undamaged.
Retreating Germans partially detroyed the fort with explosives in March 1945. It was restored during the Cold War but fixed defences fell out of favour and it was eventually taken over by the local community. The site can be visited on a self guided route and group visits can be arranged in advance.