At forty metres high, it offered a panoramic view of the region: an important strategic advantage. Promptly, German soldiers renamed the forest Bayernwald, an ode to Rupprecht von Bayern, the last Bavarian crown prince, but above all a ruthless commander who commanded the German Sixth Army.

From the hill, the Germans had a wide view of the enemy territory stretching along the Wytschate Arch, the front where trench warfare had raged for years. To reinforce their observation post, the German army constructed a vast network of trenches and bunkers.

Concrete bunkers

The soldiers could hide in one of the four concrete bunkers that have been preserved to this day. The trenches themselves have all been reconstructed and spread over a network of more than three hundred metres. A fraction of the original complex: that was over three kilometres long. Because the ground here was so soggy, the walls were reinforced from 1916 onwards with wickerwork in willow as it has been recreated today.

Mine shafts

Even more remarkable are the two mine shafts. A first shaft - Berta 4 - was discovered by chance in 1971, a second one surfaced in 2004 during works to open the complex to visitors. The German army was apprehensive about undermining their trenches.

So they excavated two mine-listening shafts at Bayernwald. Armed with stethoscopes, the soldiers descended into the underground tunnels and tried to detect and prevent any British mining activities by undermining the British tunnels in turn.

Mine battle 

Nevertheless, on 7 June 1917, during the Second Battle of Messines, the British managed to detonate dozens of mines along the Wytschaete Arch. On that day, four hundred tonnes of explosives were detonated, the loudest and largest man-made explosion up to that time in which tens of thousands of Bavarian soldiers lost their lives. 

Although the Bayernwald trench complex suffered no damage, it was captured by the Allies shortly after the explosions. Close to Bayernwald, three flooded craters still bear witness to some heavy explosions.