I have to say that just because it's the only such case doesn't in itself make it all that interesting. The graves are reverently and neatly laid out, with no hierarchy among the dead. I signed the visitors' book on behalf of myself and B; the last people before us to sign it did so on 23 December.
The stained glass windows are the artistic highlight of the Necropolis. All were designed by Maurice Langaskens, himself a prisoner in the first world war. (Click to embiggen.)
A leaflet in English (in plentiful supply) explains the iconography (again click to embiggen).
For B, the main attraction was the shadow of her own hand, starkly defined by the bright and concentrated overhead lights and the lighter floor. She isn't making any particular shape, I think, just enjoying the contrast of light and dark that she is able to create for herself.
If you want to see for yourself, it's open until 5pm in the winter and 6pm in the summer. It won't be crowded. And it's a stone's throw from two other fascinating places in Grimde, the Three Tumuli and the Church of Our Lady of the Stone.