The anti-tank ditch at Filsø

– a part of the Atlantic Wall

This bridge is adjacent to a World War II anti-tank ditch that used to continue in a northerly/southerly direction outside Filsø. At this location, across Langodde, an anti-tank ditch was excavated as a part of the Atlantic Wall with the purpose of preventing an Allied invasion via the west coast of Jutland.

In the 1945/1954 aerial photographs, the anti-tank ditch is clearly visible in the middle of the drained Filsø (partially so in the ’45 map)

Function of the Atlantic Wall – Internationally

During WW2, the German occupying forces constructed the Atlantic Wall, a fortification intended as a defence against an Allied invasion via the western European coastlines. The Atlantic Wall stretches from the border between Spain and France in the south to the northern end of Norway, a distance of approx. 5,000 km. The purpose of the Atlantic Wall was to act as a system of defence installations that did not require huge troop numbers.

Near the end of the war, most of Nazi Germany’s troops were tied up on the Eastern Front against the Soviet Union. Some 12,000 bunkers were constructed, mine fields laid, anti-tank ditches excavated, and several other military installations were erected.


In Denmark, a particularly large number of bunkers were constructed along the west coast of Jutland during the German occupation of Denmark (1940-1945) – around 2,000 in all. Many are still visible on the beaches, while others have been now covered by the sand dunes. The Atlantic Wall was not just a coastal fortification effort; installations were also placed further inland in the form of anti-tank ditches, anti-tank barriers, trenches, and minefields.  The invasion of Denmark never came to pass, and many installations were never completed before the war ended.


The German occupation affected a large number of locals along the west coast of Jutland, where the Atlantic Wall was strongly enhanced.  Military operations restricted movement for local citizens, and many houses and properties were requisitioned as quarters for German occupying troops. Henne Mølle and the barns at Filsøgård, for example, were used for this purpose.

More evidence in the landscape on the Panorama Route

When directing your bicycle along the panorama route north of Filsø, you will find the tributary to Fidde Lake, which was dredged to form an anti-tank ditch, east of Kløvbakken. This is still clearly evident from the severely sloped banks.  If you carry on to Blaabjerg, 64 metres above sea level, you will find bunkers, a machine gun position and a troop bunker.

The function of the anti-tank ditch

The function of the anti-tank ditch

38 km of anti-tank ditches were constructed in the area between Ho Bay and Ringkøbing Fjord, as well as some 90 km of barbed-wire barriers. The extensive use of timber took a heavy toll on the dune plantations of the area.

The design of the anti-tank ditches, with their depth and the right combination of angles, was well suited for holding back tanks:

  • It took 100 men one day to dig a one-kilometre stretch of ditch.
  • The anti-tank ditch was 4.5 metres wide at the top and 3 metres deep, with banks at 55 degrees.
  • Approximately 3,000 5-metre long wooden pile posts were used to shore up every kilometre.
  • 3,000 0.8-metre long wooden stakes were used to brace up every kilometre.
  • 2.4 tonnes of steel wire per kilometre of anti-tank ditch.