The Tren a las Nubes or Tren de las Nubes (English: Train to/of the Clouds) is a touristic train service in Salta Province, Argentina. The service runs along the eastern part of the C-14 line of the Ferrocarril General Manuel Belgrano, that connects the Argentine Northwest with the Chilean border in the Andes mountain range, over 4,220 metres above mean sea level, the third highest railway in the world.