The area west of the New Holland Water Line was called Fortress Holland ( Dutch : Vesting Holland ; German : Festung Holland ) , the eastern flank of which was also covered by Lake IJssel and the southern flank protected by the lower course of three broad parallel rivers : two effluents of the Rhine , and the Meuse ( or Maas ) .
The area west of the New Holland Water Line was called Fortress Holland ( Dutch : Vesting Holland ; German : Festung Holland ) .