The remains of the fortress (hisn) of the Banu Razin (r. 1011-1107), an independent Berber dynasty, are located in the present-day city of Albarracín in a mountainous region of Aragon, in northeastern Spain. Originally a walled enceinte situated atop a spur of the Sierra Albarracín mountain range, the fortress was established in the tenth century to overlook and defend the fertile river valley below. Additions to the original walled enclosure were made in the eleventh century, and eventually a town developed around the early fortress, to which strong walls and towers were later added.
Sources:
Martín Almagro Basch. 1959. Historia de Albarracín y su sierra. Teruel.
Antonio Almagro Gorbea. 1993. Urbanismo y arquitectura en la Sierra de Albarracín. Teruel: Instituto de Estudios Turolenses, p. 36-38.
Antonio Almagro Gorbea et al. 1987. Plano guía de la ciudad de Albarracín: idea, texto y maqueta. Gabinete de Fotogrametría del Instituto de Conservación y Restauración de Bienes Culturales; tramado, montaje y fotomecánica, Rugoma, S.A., Madrid. [Teruel, Spain]: Instituto de Estudios Turolenses.