Jimena de la Frontera castle was originally built by the Grenadian Moors of the Umayyad Caliphate ruling over the area of Hispania Baetica (modern Andalusia) in the 8th Century. It served as one of many castles guarding both the approach to the fortifications around Gibraltar and the Bay of Algeciras where the strategic and important Moorish stronghold and fortress of Algeciras was located.
The fortress was likely built over the ruins of the ancient city of Oba which dated to pre Roman Celtiberian period. Given its strategic location on the frontier of the Gibraltar region, this fortress proved an important Moorish stronghold throughout the Muslim domination of the Iberian Peninsula.
The castle was taken by the Jerezanos in 1430 and retaken by the Moorish Kingdom of Granada in 1451. In 1465, it was integrated into the Kingdom of Castille as the property of the crown.
The outer defenses consist of a long irregular wall that is lengthened in places to adapt to the uneven mountainous terrain. Watchtowers line this wall at regular intervals. The most well known tower is the Torre del Reloj or Albarrán (Clock Tower) and together, the towers have a very effective line of sight and defense forming an easily defensible arch of a fire zone. Various trenches also exist, all dug in different eras.
Inside the walls stands the Alcázar which was built or renovated after the Christian takeover of the castle. the Torre del Homenaje, with its large circular dome juts out of the Alcázar at a height of 13 meters making it the tallest tower of the castle. The inside of the Torre del Homenaje hides an earlier polygonal pattern tower that was presumably built over after the Christian takeover.
References:The Clementinum is a historic complex of buildings in Prague. Until recently the complex hosted the National, University and Technical libraries, the City Library also being located nearby on Mariánské Náměstí. The Technical library and the Municipal library have moved to the Prague National Technical Library at Technická 6 since 2009. It is currently in use as the National Library of the Czech Republic.
Its history dates from the existence of a chapel dedicated to Saint Clement in the 11th century. A Dominican monastery was founded in the medieval period, which was transformed in 1556 to a Jesuit college. In 1622 the Jesuits transferred the library of Charles University to the Klementinum, and the college was merged with the University in 1654. The Jesuits remained until 1773, when the Klementinum was established as an observatory, library, and university by the Empress Maria Theresa of Austria.