Belgium has three main geographical regions : the coastal plain in the north-west and the central plateau are part of the Anglo-Belgian Basin ; the Ardennes uplands in the south-east are part of the Hercynian orogenic belt . Belgium has three main geographical regions : the coastal plain in the north-west and the central plateau both belong to the Anglo-Belgian Basin ; the Ardennes uplands in the south-east are part of the Hercynian orogenic belt .