Posadas (pōsäˈħäs) [key], city (1991 pop. 211,297), capital of Misiones prov., NE Argentina, a port on the upper Paraná River. Its industries include woodworking and metallurgy. It is a point of departure for visits to Iguaçu Falls and to the nearby ruins of 17th-century Jesuit missions. The city was settled in 1849.