Algeciras is a city and a municipality of Spain belonging to the province of Cádiz, Andalusia. With a registered population as of 2020 of 123,078, it is the most populated municipality of the Campo de Gibraltar. The city is located in the western shore of the Bay of Gibraltar opposite the Rock of Gibraltar, around the mouth of the Río de la Miel, now mostly culverted in its lower course, near the southernmost end of the Iberian Peninsula and continental Europe and the Strait of Gibraltar.