​WINDAU (Russian Vindava, Lettish Wentepils), a seaport and sea-bathing resort of western Russia, in the government of Courland, at the mouth of the Windau, on the Baltic Sea, 110 m. by rail N.W. of Riga. Pop. (1897), 7132. It has a castle built in 1290. The harbour, 20 and 25 ft. deep, is free from ice all the year round. Timber, grain and other commodities are exported to the annual value of two to three millions sterling; the imports range between three-quarters and one million sterling.