If you ignore the southern most province of the Netherlands (Limburg), the next highest point is only 110 meters. Beating all other numbers on the map. And the hill in Limburg that does set the height to 322, is the hill on which the German, Belgian, and Dutch borders meet.
The only reason the Netherlands has that high a number, is because of the hill on which the Dutch, German, and Belgian borders meet. If you take Limburg out of the equation, the next highest point is 110 meters.
In two of the Dutch provinces, the highest point is a garbage dump hill.