Mallet steam locomotive #414, built in 1932 by SACM (Société Alsacienne de Constructions Mécaniques, Alsatian corporation of mechanical engineering), is pulling a mixed train through the spectacular Doux Valley at the "Passage des Etroits". Originally opened in 1891, the narrow-gauge railroad closed in 1968. It reopened in 1969 as a heritage line und operated until 2008. Services were resumed in 2013, two Mallet steam locomotives #403 and #414 are in daily service throughout the summer season.