The Schwarza is a river in Lower Austria. It is the left headstream of the Leitha.

Lower Austria is one of the nine states of Austria, located in the northeastern corner of the country. Since 1986, the capital of Lower Austria has been Sankt Pölten, replacing Vienna, which became a separate state in 1921. With a land area of 19,186 km2 (7,408 sq mi) and a population of 1.685 million people, Lower Austria is the second-most-populous state in Austria. Other large cities are Amstetten, Klosterneuburg, Krems an der Donau, Stockerau and Wiener Neustadt.