Ventspils (vĕntsˈpēls) [key], Ger. Windau, city (2011 provisional pop. 38,645), W Latvia, on the Baltic Sea, at the mouth of the Venta River. An ice-free seaport, it exports oil brought by pipeline or rail from Russia. Ventspils also has shipyards, fisheries, and varied manufactures. The city grew around a 13th-century castle of the Livonian Brothers of the Sword and was chartered in 1314.