Especially until the fall of the Iron Curtain Hardegg was very isolated. To the Czech Republic there is only the Thaya Bridge Hardegg - Čížov. This is also reflected in the decreasing number of inhabitants. As the only economic factor the growing tourism could be mentioned. The highest population figure since the beginning of statistical records through the state was recorded in 1890 than were counted in Hardegg 3209 inhabitants.
Source: http://de.wikipedia.org/wiki/Hardegg_(Nieder%C3%B6sterreich) (German)