Irrel is a small town next to the border with Luxembourg and here can remains of the West Wall be found. The origins of the West Wall date back to the First World War when a number of defensive positions were built called the Hindenburg line. But the West Wall at Irrel began its construction in 1938 and was completed in 1940. The West Wall was a response to France’s Maginot line and would be a defense against France. The west embankment, or the Siegfried line as it was also called, stretched from the Dutch border down to the Swiss border and consisted of about 18,000 bunkers and pillboxes. When France declared war on Germany on September 3, 1939, Germany mobilized the West Wall to meet a possible French attack. But that never happened. Nor was it used when Germany attacked Western Europe in the spring of 1940. Not until the Western allied landing in Normandy in June 1944 did the West Wall mobilized again. But it was not until autumn 1944 heavy fightings occured when the Wall became a difficault obstacle to overcome for the allies during their advance eastward.
Current status: Preserved with museum (2008).
Location: 49°51'05.42" N 06°27'13.14" E
Get there: Car.
Follow up in books: Neil Short and Chris Taylor: Germany´s West Wall: The Siegfried Line (Fortress) (2004).
The museum is small and has limited opening hours, but you can visit the outdoors 24/7. From there you have a nice view of the city of Irrel. Keep in mind that the temperature inside the mountain is about 10 degrees Celsius all year round.