Castle of los Vélez Monument · Mazarrón, Bajo Guadalentín, Murcia Fortress raised at the end of the fifteenth century by the Fajardo family on a small hill overlooking the centre of Mazarrón, whose origin goes back to the granting of the alum mines; at the end of the nineteenth century a mine was opened in its former residential area which came to bury part of the fortification. Photo: Yolanda95 (CC BY-SA 4.0) What to see and do in Mazarrón