Historically, the origins of the settlement in Bornos are unclear. But ruins of an old Roman city, the city of Carissa Aurelia, was found in the area. The Muslim conquest left more for substantiation because of the Castle of Fontanar that became a center of its community until Christians led by Fernando III in 1250 conquered the settlement. Ultimately, the town was ceded to powerful families, first to the Ponce de León family and afterwards to the Riberas in the late 1300’s. It slowly gained fame as a recreational destination for Spanish nobility.
