Îlot Sacré (now called the Free Commune of Ilot Sacre)has a very singular history behind it. It all started in the fifties for the 1958 World Exposition. The powers that be wanted to widen a number of streets to speed up traffic movement in the Grand 'Place area. Three streets in particular were targeted much to the dismay and angst of the merchants with shops on those streets. It seemed a whole series of buildings on the even side of the Rue des Bouchers were slated to disappear or have their fronts limited. The rule was their facades had to be a continuation of the restaurant La Terrasse (still in existence today).
The Petite Rue des Bouchers faced an even potentially greater decimation that would leave only a small part of one baker's shop in existence. This riled the shopkeepers, and the area's inhabitants who had a great deal to day about that idea. At the end of the World Expo what happened instead was a committee was struck to study the possibility of creating islets. On March 21st 1960, a special plan was adopted in order to prevent the building of modern constructions and to preserve, harmonize and restore the existing facades. Along with this came strict town-planning standards. E.g. It was forbidden to hang perpendicular sign-boards and they had to be written in gothic letters. Only indirect lighting was allowed. This area of Brussels will appeal to your sense of whimsy and is well worth exploring.