The Lang Biang Cog Railway (Thap Cham to Da Lat) was a metre gauge cog railway located in southern Vietnam (French Indochina when construction began in 1903). It connected a major north/south rail line along the coast at Thap Cham to Da Lat inland at an elevation of 1,488 metres until it was dismantled in 1974 following the end of the Vietnam War.
 

It's not possible to trace the abandoned line today on Google's maps but approximate station locations along the route are displayed here.
 

Today the only remaining adhesion trackage lies between Da Lat and Trai Mat, a distance of 7 kilometres. A Soviet-era diesel locomotive pulls passenger cars as a tourist attraction. The round trip takes 2 hours but catching the train can be tricky. It only departs Da Lat after 25 people have bought tickets.
 

The three rack sections of the Lang Biang Cog Railway used to lie between Song Pha and Trai Mat, each with different grades varying between 6 and 12 percent.
 

Two of the Swiss built HG 4/4 locomotives that operated in Vietnam have been returned to Switzerland.
 

The Dampfbahn Furka-Bergstrecke (DFB) currently operates HG 4/4 number 704 over its route between Realp and Oberwald.