Besançon's Vauban citadel has been listed as a UNESCO World Heritage Site. Louis XIV of France conquered the city for the first time in 1668, but the Treaty of Aix-la-Chapelle returned it to Spain within a matter of months. While it was in French hands, the famed military engineer Vauban visited the city and drew up plans for its fortification. The Spaniards built the main centre point of the city's defences, 'la Citadelle', siting it on Mont Saint-Étienne, which closes the neck of the oxbow that is the site of the original town. In their construction, the Spaniards followed Vauban's designs.
In 1674, French troops recaptured the city, which the Treaty of Nijmegen (1678) then awarded to France. As a result of control passing to France, Vauban returned to working on the citadel's fortifications, and those of the city. This process lasted until 1711, some 30 years, and the walls built then surround the city. Between the train station and the central city there is a complex moat system that now serves road traffic. Numerous forts, some of which date back to that time and that incorporate Vauban's designs elements sit on the six hills that surround the city: Fort de Trois Châtels, Fort Chaudanne, Fort du Petit Chaudanne, Fort Griffon, Fort des Justices, Fort de Beauregard and Fort de Brégille. The citadel itself has two dry moats, with an outer and inner court. In the evenings, the illuminated Citadelle stands above the city as a landmark and a testament to Vauban's genius as a military engineer.
The Citadel is built on top of a large syncline on a rectangular field crossed across its width by three successive bastions (enclosures, or fronts) behind which extend three plazas. The whole is surrounded by walls covered by circular paths and punctuated by watchtowers and sentry posts. The walls are up to 15 to 20 metres high with a thickness between 5 and 6 metres.References:
The Mosque–Cathedral of Córdoba, also known as the Great Mosque of Córdoba and the Mezquita is regarded as one of the most accomplished monuments of Moorish architecture.
According to a traditional account, a small Visigoth church, the Catholic Basilica of Saint Vincent of Lérins, originally stood on the site. In 784 Abd al-Rahman I ordered construction of the Great Mosque, which was considerably expanded by later Muslim rulers. The mosque underwent numerous subsequent changes: Abd al-Rahman II ordered a new minaret, while in 961 Al-Hakam II enlarged the building and enriched the Mihrab. The last of such reforms was carried out by Almanzor in 987. It was connected to the Caliph"s palace by a raised walkway, mosques within the palaces being the tradition for previous Islamic rulers – as well as Christian Kings who built their palaces adjacent to churches. The Mezquita reached its current dimensions in 987 with the completion of the outer naves and courtyard.
In 1236, Córdoba was conquered by King Ferdinand III of Castile, and the centre of the mosque was converted into a Catholic cathedral. Alfonso X oversaw the construction of the Villaviciosa Chapel and the Royal Chapel within the mosque. The kings who followed added further Christian features, such as King Henry II rebuilding the chapel in the 14th century. The minaret of the mosque was also converted to the bell tower of the cathedral. It was adorned with Santiago de Compostela"s captured cathedral bells. Following a windstorm in 1589, the former minaret was further reinforced by encasing it within a new structure.
The most significant alteration was the building of a Renaissance cathedral nave in the middle of the expansive structure. The insertion was constructed by permission of Charles V, king of Castile and Aragon. Artisans and architects continued to add to the existing structure until the late 18th century.
The building"s floor plan is seen to be parallel to some of the earliest mosques built from the very beginning of Islam. It had a rectangular prayer hall with aisles arranged perpendicular to the qibla, the direction towards which Muslims pray. The prayer hall was large and flat, with timber ceilings held up by arches of horseshoe-like appearance.
In planning the mosque, the architects incorporated a number of Roman columns with choice capitals. Some of the columns were already in the Gothic structure; others were sent from various regions of Iberia as presents from the governors of provinces. Ivory, jasper, porphyry, gold, silver, copper, and brass were used in the decorations. Marvellous mosaics and azulejos were designed. Later, the immense temple embodied all the styles of Morisco architecture into one composition.
The building is most notable for its arcaded hypostyle hall, with 856 columns of jasper, onyx, marble, granite and porphyry. These were made from pieces of the Roman temple that had occupied the site previously, as well as other Roman buildings, such as the Mérida amphitheatre. The double arches were an innovation, permitting higher ceilings than would otherwise be possible with relatively low columns. The double arches consist of a lower horseshoe arch and an upper semi-circular arch.