Winterthur is a city in the canton of Zürich in northern Switzerland. It has the country's sixth largest population, estimated at more than 100,000 people. Today Winterthur is a service and high-tech industry centre, but many people make use of its proximity to Zürich, which lies approximately 30km to the south-west, and only 18 minutes by train.The official language of Winterthur is (the Swiss variety of Standard) German, but the main spoken language is the local variant of the Alemannic Swiss German dialect. In the local dialect and by its inhabitants, it is usually abbreviated as Winti.Winterthur is connected to Germany and Italy by direct trains and enjoys links to Zürich Airport. It is also a regional transport hub: the A1 motorway from Geneva through to St. Margrethen connects in Winterthur with the A4 motorway heading north toward Schaffhausen and the A7 motorway heading close to the Swiss-German border at Kreuzlingen. There are also roads leading to other places such as Turbenthal. Winterthur Hauptbahnhof is one of the busiest railway stations in Switzerland.HistoryVitudurum was a vicus in what is now Oberwinterthur during the Roman era (1st century BC to 3rd century AD), fortified into a castrum at the end of the 3rd century, apparently in reaction to the incipient Alamannic invasion.