Weird

If Belgium doesn't exist, then what's in its location on the map?

There is nothing there! France shares a border with the Netherlands. Notice how Belgium is depicted as being wedge shaped? They simply pulled apart the French border from the coast all the way to Luxembourg and slipped Belgium in. Since they control the maps, no one notices the geographic inconsistencies arising from the spatial compressions and deformations needed to make it fit, the effects of which are subtle since they are spread over a large area: the ratio of actual distances to distances stated on maps and road signs increases by a gradual curve as you approach the France-Netherlands/Germany border from Paris to the west and Hannover to the east.