SAN FERNANDO  , a seaport of southern Spain, in the province of Cadiz, on the Isla de Leon, a rocky island among the salt marshes which line the southern shore of Cadiz Bay . Pop . (1900), 29,635 . San Fernando is one of the three principal naval ports of Spain; together with Ferrol and Cartagena it is governed by an admiral who has the distinctive title of captain-general . The town is connected with Cadiz (4 m . N.W.) by a railway, and there is an electric tramway from the arsenal (in the suburb of La Carraca) to Cadiz . The principal buildings are government workshops for the navy, barracks, a naval academy, observatory, hospital, bull-ring and a handsome town hall . In the neighbourhood salt in largely produced and stone is quarried; the manufactures include spirits, beer, leather, esparto fabrics, soap, hats, sails and ropes; and there is a large iron-foundry . San Fernando was probably a Carthaginian settlement . On a hill to the S. stood a temple dedicated to the Tyrian Hercules; to the E. is a Roman bridge, rebuilt in the 15th century after partial demolition by the Moors . The arsenal was founded in 1790 . During the Peninsular War the cortes met at San Fernando (181o), but the present name of the town dates only from 1813; it was previously known as Isla de Leon .