Cadiz (Cádiz), a maritime province in the extreme south of Spain, formed in 1833 of districts taken from the province of Seville; and bounded on the N. by Seville, E. by Málaga, S.E. by the Mediterranean sea, S. by the Straits of Gibraltar, and W. by the Atlantic Ocean. Pop. (1900) 452,659; area 2834 sq. m.; inclusive, in each case, of the town and territory of Ceuta, on the Moroccan coast, which belong, for administrative purposes, to Cadiz. The sea-board of Cadiz possesses several features of exceptional interest. On the Atlantic littoral, the broad Guadalquivir estuary marks the frontier of Seville; farther south, the river Guadalete, which waters the northern districts, falls into the magnificent double bay of Cadiz; farther south again, is Cape Trafalgar, famous for the British naval victory of 1805. Near Trafalgar, the river Barbate issues into the straits of Gibraltar, after receiving several small tributaries, which combine with it to form, near its mouth, the broad and marshy Laguna de la Janda. Punta Marroqui, on the straits, is the southernmost promontory of the European mainland.
The most conspicuous feature of the east coast is Algeciras Bay, overlooked by the rock and fortress of Gibraltar. The river Guadiaro, which drains the eastern highlands, enters the Mediterranean close to the frontier of Málaga. In the interior there is a striking contrast between the comparatively level western half of Cadiz and the very picturesque mountain ranges of the eastern half, which are well wooded and abound in game. The whole region known as the Campo de Gibraltar is of this character; but it is in the north-east that the summits are most closely massed together, and attain their greatest altitudes in the Cerro de San Cristobal (5630 ft.) and the Sierra del Pinar (5413 ft.).
The climate is generally mild and temperate, some parts of the coast only being unhealthy owing to a marshy soil. Severe drought is not unusual, and it was largely this cause, together with want of capital, and the dependence of the peasantry on farming and fishing, that brought about the distress so prevalent early in the 20th century. The manufactures are insignificant compared with the importance of the natural products of the soil, especially wines and olives. Jerez de la Frontera (Xeres) is famous for the manufacture and export of sherry. The fisheries furnish about 2500 tons of fish per annum, one-fifth part of which is salted for export and the rest consumed in Spain. There are no important mines, but a considerable amount of salt is obtained by evaporation of sea-water in pans near Cadiz, San Fernando, Puerto Real and Santa Maria. The railway from Seville passes through Jerez de la Frontera to Cadiz and San Fernando, and another line, from Granada, terminates at Algeciras; but at the beginning of the 20th century, although it was proposed to construct railways from Jerez inland to Grazalema and coastwise from San Fernando to Tarifa, travellers who wished to visit these places were compelled to use the old-fashioned diligence, over indifferent roads, or to go by sea.
The principal seaports are, after Cadiz the capital (pop. 1900, 69,382), Algeciras (13,302), La Línea (31,862), Puerto de Santa Maria (20,120), Puerto Real (10,535), the naval station of San Fernando (29,635), San Lucar (23,883) and Tarifa (11,723); the principal inland towns are Arcos de la Frontera (13,926), Chiclana (10,868), Jerez de la Frontera (63,473), Medina Sidonia (11,040), and Véjer de la Frontera (11,298). These are all described in separate articles. Grazalema (5587), Jimena de la Frontera (7549), and San Roque (8569) are less important towns with some trade in leather, cork, wine and farm produce. They all contain many Moorish antiquities, and Grazalema probably represents the Roman Lacidulermium. (See also Andalusia.)