Algeciras is a city and municipality located in the province of Cádiz within the Andalusia region of Spain. Situated at the southernmost end of the Iberian Peninsula and continental Europe, it lies on the western shore of the Bay of Gibraltar, directly opposite the Rock of Gibraltar near the Strait of Gibraltar.
The city is positioned around the mouth of the Río de la Miel, which has been mostly culverted in its lower course. As of 2020, Algeciras had a registered population of 123,078, making it the most populated municipality in the Campo de Gibraltar region.