A viaduct is a bridge composed of several small spans for crossing a valley or a gorge. The term viaduct is derived from the Latin via for road and ducere to lead something. However, the ancient Romans did not use that term per se; it is a modern derivation from an analogy with aqueduct. Like the Roman aqueducts, many early viaducts comprised a series of arches of roughly equal length. Viaducts may span land or water or both.
The longest viaduct in antiquity may have been the Pont Serme which crossed wide marshes in southern France. Viaducts are commonly used in many cities that are railroad centers, such as Chicago, Atlanta, Birmingham, London, and Manchester. These viaducts cross the large railroad yards that are needed for freight trains there, and also cross the multi-track railroad lines that are needed for heavy railroad traffic. These viaducts keep highway and city street traffic from having to be continually interrupted by the train traffic. Likewise, some viaducts carry railroads over large valleys, or they carry railroads over cities with many cross-streets and avenues.
Scotland (Scottish Gaelic: Alba (Scottish Gaelic: [ˈal̪ˠapə] ( listen))) is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the southwest. In addition to the mainland, Scotland is made up of more than 790 islands including the Northern Isles and the Hebrides.
Edinburgh, the country's capital and second largest city, is one of Europe's largest financial centres. Edinburgh was the hub of the Scottish Enlightenment of the 18th century, which transformed Scotland into one of the commercial, intellectual and industrial powerhouses of Europe. Glasgow, Scotland's largest city, was once one of the world's leading industrial cities and now lies at the centre of the Greater Glasgow conurbation. Scottish waters consist of a large sector of the North Atlantic and the North Sea, containing the largest oil reserves in the European Union. This has given Aberdeen, the third largest city in Scotland, the title of Europe's oil capital.