SAN FERNANDO, formerly ISLA DE LEON, a fortified city of Spain, in the province of Cadiz, near the head of the inner bay, and 91 miles by rail from the city of Cadiz (see vol. iv. p. 627), is a modern town with straight and level streets, two churches, two hospitals, several barracks, and a school of navigation, with an observatory. It has considerable trade in the salt produced in the neighbouring "salinas." The population within the municipal limits (which include the " poblacion" of San Carlos and the naval arsenal of La Carrara) was returned as 26,346 in 1877.