La Trochita (official name: 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 "The little gauge" though it is sometimes translated as "The Little Narrow Gauge" in Spanish while "trocha estrecha", "trocha angosta" in Argentina, is often used for a generic description of "narrow gauge."