Posadas is the capital city of the Argentine province of Misiones, located at the south of the province, on the left-hand (western) shore of the Paraná River, opposite Encarnación, Paraguay. The city has an area of 965 km² and a population of 255,052 ().
Posadas is the provincial centre of the government, culture and economy. Furniture, tobacco, food, textile, and construction are the most important industries. Other important economical activities are the commerce and services.
Posadas is connected to the Paraguayan city of Encarnación by the San Roque González de Santa Cruz Bridge. The port, once of great economical importance, is used for sport vessels, carrier of passengers and some boats for sand transport. The city is located on National Route 12, some 1,300 kilometres from Buenos Aires. The General José de San Martín Airport , at coordinates , is 7 kilometres from the city, and serves regular flights to Buenos Aires.
Father Roque González de Santa Cruz founded a town called Anunciación de Itapúa on March 25 1615, but ten years later the settlement was moved to the other side of the Paraná River to the present location of Encarnación in Paraguay.
The first settlement was not completely abandoned, and a new San José reduction was settled there in 1628. In 1867, during the War of the Triple Alliance, the Brazilians set up the Trinchera de San José military base there. In 1879, at the end of the war, the town was renamed to Posadas after Gervasio Antonio de Posadas, the Supreme Director of the Argentine Confederation.
On December 22 1881, the limits of the Misiones Federation were drawn, leaving Posadas within the territory of current Corrientes Province. On July 30 1884 the National Congress decided to give Posadas to Misiones Province, and name it its capital.