It was just over 7 km (4 mi) long and ran from Oviedo to the iron ore mines in the Villapérez and Naranco areas of Asturias from 1880 to 1916.

[2][3] The construction of the mining railway began in 1879, to haul iron ore to the northern station in Oviedo, from where it could be transported to Mieres.

On 23 March 1879, the Compañia Numa Gilhou changed its name to Sociedad Fábrica de Mieres.

These are respectively interbedded between ferruginous sandstones of the Devonian and rocky limestones that have been folded and uplifted as an anticline.

Exploitation in the Villapérez area began in 1879 with the opening of galleries in the Fuentenueva, Piquete and Gamoneda gorges, which divided the exploitation into four levels (pisos) or workshops (talleres) with a height of 30 metres (100 ft), the galleries being almost 400 metres (1,300 ft) long.

The Naranco stratum in this area lies either vertically, obliquely or horizontally, so that mining could partly take place without backfilling and without pillars.

On 1 February 1880, the original 7,101-metre (7,766 yd) long mining railway between the Villapérez area and the northern station of Oviedo operated by the Compañía de los Ferrocarriles de Asturias, Galicia y León was inaugurated with an original length of 7.1 km (4.4 mi).

The two cable drums were connected by a horizontal axle and both installed at the top of the inclined lift.

Metal sections manufactured in the Meres factory were used to build two bridges over small streams.

On 1 February 1880, the original 7.101-kilometre (4.412 mi) mining railway between the Villapérez area and the northern station of Oviedo operated by the Compañía de los Ferrocarriles de Asturias, Galicia y León was inaugurated with an original length of 7.1 km (4.4 mi).

The track material used for the permanent way of the mining railway was entirely manufactured by the Sociedad Fábrica de Mieres.

The sleepers were made of oak wood with a length of 1 metre (3 ft 3 in), and a total of 16,083 pieces were used.

From the summit of this plain, a 720-metre (790 yd) long branch line led westwards to the 'Narancti' group.

[4] The railway was operated by Couillet steam locomotives, the first of which had been manufactured as early as 1877, shortly before Paul Decauville had demonstrated a similar Corpet-Louvet locomotive in 1878 at the Exposition Universelle in the Jardin d'Acclimatation: The freight wagons used to transport ore had a wooden frame consisting of two longitudinal beams and two cross beams connected lengthwise by a draw bolt.

Before the opening of the railway, the Fábrica de Mieres imported two passenger carriages, each with eight seats, from abroad with the intention of using them to transport personnel from Oviedo to Villaperez, such as engineers, managers, etc.