Langemark German War Cemetery

A powerful image.

I am curious regarding the purpose and symbolism, if any, behind this structure?

This is the entrance hall to the cemetery. Inside the passage are video screen showing old footage from WW1 and graphic information about the war. The after the treaty of Versaille , it was decided that the Germans buried in Flanders would not get white tombstones, instead they would only get black marble slabs laying flat on the ground. It's quite a powerful sight and idea. This stark, flat, hollow black slab in in keeping with the doom of rest of the cemetery. It's not a glorious, shining and victorious monument to those who fed the guns.

Looks suitably grim, and a huge tragedy for those on both sides of the trench...who were the same people at the mercy of incompetent politicians.