Jerez de la Frontera or simply Jerez, also cited in old English-language sources as Xeres, is a city and municipality in the province of Cádiz i…Jerez de la Frontera or simply Jerez, also cited in old English-language sources as Xeres, is a city and municipality in the province of Cádiz in the autonomous community of Andalusia, Spain. Located in southwestern Iberia, it lies on the Campiña de Jerez, an inland low-land plain crossed by the Guadalete river, midway the Atlantic Ocean, the Guadalquivir river and the western reaches of the Subbaetic System.