San Fernando (săn fərnănˈdō) [key], city (1991 pop. 144,761), Buenos Aires prov., E Argentina. It is a district administrative center in the Greater Buenos Aires area. The city was established in 1806 to replace the port of Las Conchas, which had been destroyed by a storm. An important landmark is the Juan N. Madero museum and library. San Fernando is connected to other Argentine cities by three rail lines, a national highway, and an airport.