States of Austria arable terrain. The other five states, in contrast, are located in the Alps and thus are comparatively unsuitable for agriculture. Their terrain is also relatively unfavourable to heavy industry and long-distance trade. Accordingly, the population of what now is the Republic of Austria has been concentrated in the former four states since prehistoric times. Austria's most densely populated state is the city-state of Vienna, the heart of what is Austria's only metropolitan area. Lower Austria ranks only fourth with regard to population density even though it contains Vienna's suburbs; this is due to large areas of land being predominantly agricultural.
States of Germany the . German reunification in 1990, in which the area of the German Democratic Republic (East Germany) became part of the Federal Republic, was performed by the way of ascent of the re-established eastern states of Brandenburg, Mecklenburg-West Pomerania ('), Saxony ('), Saxony-Anhalt ('), and Thuringia (') to the Federal Republic, as well as the de-facto reunification of West and East Berlin into Berlin and its establishment as a full and equal state. A regional referendum in 1996 to merge Berlin with surrounding Brandenburg as "Berlin-Brandenburg" failed to reach the necessary majority vote in Brandenburg, while a majority of Berliners