The Irati Railway is called after the company that operated it, “Sociedad El Irati.” This company was not originally a railway one: it was mainly centred on forestry activities in Navarre’s Pyrenean mountains, specifically in the renowned Irati Forest. At the same time, in the surroundings of Aoiz, it built a hydroelectric power plant, which not only supplied its own sawmill but also sold electricity to nearby villages, and even as far as Pamplona. As part of its business, this company decided to build a railway that would basically be used to transport timber from Aoiz to Pamplona. However, the transportation of other goods and passengers also became very important.

This small metric-gauge railway was opened in 1911, having been built with a tramway license. This resulted in a considerable reduction in costs, enabling it to operate in Pamplona as a city tram, along the streets, and in rural areas to alternate between sections of its own platform and country roads, making use, for example, of all the bridges over the itinerary’s numerous river courses.

The railway line had access to Aoiz, where the sawmill was located, although this section was conceived as a short three-kilometre branch line. The main line continued on for another 26 km from Empalme de Aoiz towards Lumbier and Sangüesa, passing through Foz de Lumbier in the final section. A total of 59 km of metric-gauge tracks were laid, being the first narrow-gauge railway that was electrified in Spain. Curiously, its voltage was similar to that of the modern high-speed AVE train (5000 VAC), although in the city section through Pamplona it dropped to 750 VCC. Certainly, its speed was nothing like that of its modern successor. Due to economic difficulties in the fifties, as a result of the boom in road transport, the railway was closed in April 1955.