The Tren A Las Nubes Train, Salta Province, Argentina

History
The construction of the railway started in 1921, to connect the North of Argentina with Chile across the Andes, and to serve the borax mines of the area. The viaduct La Polvorilla, the highest of the line, was finished on 7 November 1932. The complete railway was inaugurated on 20 February 1948, but it was not until the late 1970s that it started being visited by tourists. The route was designed by American engineer Richard Fontaine Maury, after whom one of the stations has been named.