La Trochita, (El Viejo Expreso Patagónico), in English known as the Old Patagonian Express, is a 750 mm (2 ft 5 1⁄2 in) narrow gauge railway in Patagonia, Argentina using steam locomotives. The nickname La Trochita means literally "little gauge" though it is sometimes translated as "The Little Narrow Gauge" in Spanish while "trocha estrecha" is often used for a generic description of "narrow gauge." The Trochita railway is 402 km in length and runs through the foothills of the Andes between Esquel and El Maitén in Chubut Province and Ingeniero Jacobacci in Río Negro Province, originally it was part of Ferrocarriles Patagónicos, a network of railways in southern Argentina. Nowadays, with its original character largely unchanged, it operates as a heritage railway and was made internationally famous by the 1978 Paul Theroux book The Old Patagonian Express, which described it as the railway almost at the end of the world. The line is in possession of 22 steam locomotives, 11 Henschel and 11 Baldwins 2-8-2 "Mikado" type locomotives, 7 of which are currently operable. The locomotives are oil fired and have been in continuous service since its introduction. There are no diesel engines in use anywhere on the line. The present rolling stock as the locomotives date from 1922, with the exception of the dining car and some first class carriages that were constructed in 1955. Source Wikipedia.