Naours was a popular place for soldiers to visit during the war. It was discovered by locals in the 3rd century and used as a hiding place for villagers and their livestock during wars and troubles, right through until the 17th century.

The caves and passageways then fell into obscurity and were largely forgotten until they were rediscovered by a local abbot in the late 1800s. They became a popular local tourist attraction and were visited by thousands of Allied troops during the war.

Today, the caves and tunnels contain more than 3,000 examples of graffiti from the Great War. It is the largest known collection of inscriptions drawn by First World War soldiers on the Western Front.  But they were forgotten until they were rediscovered by French archaeologist Gilles Prilaux in 2014.