The very name Trenillo (literally, the “Little Train”) evokes a narrow-gauge railway —although in time the line was converted to standard gauge. The idea behind the project was to connect Quintanar de la Orden to the national rail network, from which it had been left isolated. As early as 1864, due to pressure from local municipalities, work began to link the town with Alcázar de San Juan, and some 26 km of earthworks were completed before the project was abandoned.  It wasn’t until 1909 that local businessmen from Quintanar finally succeeded in launching a line —this time in narrow gauge, running not to Alcázar but to Villacañas, via La Puebla de Almoradiel and La Villa de Don Fadrique.

But the venture was plagued with problems from the start: poor-quality track, inadequate rolling stock, and forced transfers of passengers and freight at Villacañas due to the break of gauge.  Only Spain’s neutrality during the First World War, which temporarily boosted traffic, allowed the company to keep afloat through the 1920s. Optimism led to a change to standard gauge, allowing direct connection to the national network and the arrival of new rolling stock, notably railcars that were faster and cheaper to operate. Yet this revival proved short-lived. The Civil War dealt a severe blow, and the line never fully recovered. Integrated into Renfe in 1941, the railway saw no real improvement. By 1969 passenger traffic was already heavily reduced, and in 1984 all passenger services were discontinued. The last freight train ran in 1990, after which the tracks were lifted for good.