The Treno Gottardo runs from three cities in the north to the sunny city of Locarno in the south.The Treno Gottardo train as it passes by the Church of Wassen.Credit: Thomas Kessler Visuals/Travel SwitzerlandKey PointsA rail journey is the ideal way to see Switzerland's different regions.The scenic Treno Gottardo runs on a historic rail line from the country's north, over the Alps, and to a popular resort city in the south.Along the way, passeng…