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 Baths of Caracalla were the second largest Roman public baths, or thermae, in Rome. It was built between AD 212 and 217, during the reigns of Septimius Severus and Caracalla. They would have had to install over 2,000t of material every day for six years in order to complete it in this time.
The baths remained in use until the 6th century when the complex was taken by the Ostrogoths during the Gothic War, at which time the hydraulic installations were destroyed. The bath was free and open to the public. The earthquake of 847 destroyed much of the building, along with many other Roman structures.
The building was heated by a hypocaust, a system of burning coal and wood underneath the ground to heat water provided by a dedicated aqueduct. It was in use up to the 19th century. The Aqua Antoniniana aqueduct, a branch of the earlier Aqua Marcia, by Caracalla was specifically built to serve the baths. It was most likely reconstructed by Garbrecht and Manderscheid to its current place.
In the 19th and early 20th century, the design of the baths was used as the inspiration for several modern structures, including St George's Hall in Liverpool and the original Pennsylvania Station in New York City. At the 1960 Summer Olympics, the venue hosted the gymnastics events.