Architecture of Luxembourg
The architecture of Luxembourg probably extends back to the Treveri, a Celtic tribe who prospered in the 1st century BC. A few ruins remain from the Roman occupation but the most significant contributions over the centuries have been the country's castles and churches. Today there is a veritable architectural boom as Luxembourg's economic prosperity provides a basis for developments in the financial, EU and cultural sectors with a number of world-class buildings. History. The architecture of Luxembourg appears to have its origins in the 1st or 2nd century BC when the Treveri, a prosperous  Celtic tribe, developed an oppidum on Titelberg in the south-western corner of the country. The Romans, who occupied the area from 53 BC until the middle of the 5th century, are responsible for the remains of a number of villas across the country, especially in Echternach, Mamer and Goeblange. The Echternach site covers a huge area (118 by 62 metres), where there was a luxurious mansion from about 70 AD with 40 (later 60) rooms. It had "balneae", a water heating system as well as additional buildings serving the surrounding farming community. Castles and churches. Castles. One of the  country's most famous monuments, the imposing Castle of Vianden, was built between the 11th and 13th centuries on the site of a Gallo-Roman castellum. Initially designed as a fort, a square tower, a kitchen, a chapel and living rooms were added around 1100. During the 12th century, a new tower containing living quarters was built together with a prestigious new decagonal chapel. So as to impress the House of Luxembourg, the counts of Vianden constructed a new two-storey palace measuring 10 by 13 metres at the beginning of the 13th century, attaching it to the chapel by  means of a magnificent gallery. The final alterations took place in the middle of the 13th century when the Gothic style was introduced throughout the building. Luxembourg has many other medieval castles, most of them now in ruins. Some of the more interesting ones are listed below: Churches. Luxembourg also has a number of architecturally interesting churches. The Abbey of Echternach (700) is the oldest Anglo-Saxon monastery in continental Europe. After the original buildings had burnt down in 1017, a new abbey was built. The church was originally Romanesque in style, but there were Gothic additions in the 14th  and 16th centuries. Bridges. Luxembourg City has several distinctive bridges. The Adolphe Bridge, connecting the old town centre or Ville Haute to the more recent Gare district to the south, was completed by French engineer Paul Séjourné in 1902. The bridge consists of a large central arch flanked by smaller arches on either side. With a span of 84.65 m (277.72 ft), the central arch was the largest of its day. The bridge is currently being widened to accommodate a new tram line. The design of Walnut Lane Bridge in Philadelphia was copied from the Adolph Bridge. The Passerelle, designed  by Edouard Grenier and Auguste Letellier, was completed in 1861. The bridge is 290 m (951 ft) long, with 24 arches, and rises 45 m (148 ft) above the Pétrusse valley floor. It connects the city center with the railway station to the south. The Grand Duchess Charlotte Bridge, completed in 1965, was designed by the German architect Egon Jux. Carrying road traffic on three lanes in each direction, it connects the city centre with European Institutions and the financial district on the Kirchberg Plateau. It towers above the little bridge known as "de Béinchen" (1786) which forms part of  Vauban's fortifications. The two-storey Pont du château (Castle Bridge), built of sandstone by the Austrians in 1735, replaces an old drawbridge between the cliffs of the Bock. It provides access to the eastern end of the old town up the hill from Clausen. In addition to the roadway at the top, it also has three other means of crossing: one across the four upper arches, one through a spiral staircase inside the lower arch and one under Sosthène Weis, the street below, through a passage leading to the casemates. Other buildings of note. There are a number of  other buildings of architectural interest in the city of Luxembourg. Contemporary developments. The 1990s were characterised by a progressive internationalization of Luxembourg's art scene, marked by the designation of the City of Luxemburg as World Heritage Site in 1994 and European Capital of Culture in 1995. This process was manifest in the architectural debate around the design of the new National Museum of History and Art by Christian Bauer et Associés, opened in 2002. International design competitions also contributed to this process, attracting notable architects like Dominique Perrault, winner of the 1996 competition for a major extension of the  Court of Justice of the European Union and Bolles+Wilson, winners of the 2003 design competition for the National Library of Luxembourg. There are several other fine examples of modern architecture in Luxembourg. These include: