In the photograph you can see the back of the second granite slab which has the text in French. Interesting that English seems to have replaced Flemish here. The text does not state why the stones/plaques were placed here but we are informed that they commemorate the opening of the European Parliament building. Having cycled past these things many times without thinking that they might be commemorative, we think they fail on a number of fronts: prominence, content and attractiveness. Perhaps they are an example of design by committee.
Site: SEAP (1 memorial)
1000, rue du Remorqueur, mini roundabout north of entrance to European Parliament