LEON, Isla de, an island on the S.W. coast of Spain, province of Cadiz, separated from the mainland by a narrow but deep strait, called Santi Petri, is about 12 miles in length from S.E. to N.W., and from 1 to 3 miles in breadth. The broadest portion is next the mainland, while the narrowest part, which forms a long spit, juts into the Bay of Cadiz. On the extremity of this peninsula stands the city of Cadiz, cut off from the rest of the island by a fortification called La Cortadura. The surface of Isla de Leon is flat and covered with saline marshes, from which large quantities of salt are extracted by the inhabitants. Communication with the continent is effected by means of an ancient bridge thrown over the Santi Petri. The chief towns on the island are Cadiz and San Carlos.