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.
Concordats with individual states of Germany Concordats with individual states of Germany Concordats between the Holy See and individual German states were concluded both before and after the unification of Germany in the 1870s. Early examples include: In addition to the Reichskonkordat at the federal level, there are concordats between the Holy See and thirteen German states (Länder). This is because the individual states of the German federation have competencies in legislation with respect to education, culture and, to some extent, finance. In 1929 Prussia and the Holy See signed the Prussian Concordat (), which remains still valid for formerly Prussian territory within some of its