Ostrau, the name of two Austrian towns in the OstrauKarwin coal-mining district. (1) Ma.hrisch-Ostrau (Moravian Ostrau), a town in Moravia, 95 m. N.E. of Briinn by rail. Pop. (5900) 30,125. It is situated on the right bank of the Ostrawitza, near its confluence with the Oder, and it derives its importance from the neighbouring coal mines, and the blast furnaces and iron-works which they have called into existence. The manufactures comprise sheet-iron, boilers, zinc, brick and tiles, paraffin, petroleum, soap and candles. The Rothschild iron-works at Witkowitz are in the vicinity. (2) Polnisch-Ostrau (Polish Ostrau), a mining town in Austrian Silesia, opposite MahrischOstrau. Pop. (1900) 18,761, mostly Czech. It has large coal mines, which form the south-western portion of the extensive Upper Silesian coal fields, the largest Austrian deposit.