The Algarrobillo well is a water collection point that supplied the suburbs and the citadel, and which, due to its structure, functioning, constructive aspects and location, corresponds to a Nasrid-era typology. It consists of a water mine, a 57.3-metre-long gallery, a later, much shorter gallery and a cistern. The water emanating from the well flows down by simple gravity through a slight slope of the first gallery towards the cistern, which stores it up to a limit to prevent it from overflowing.