León - Asturias Line

New rail access between the Meseta and Asturias


The construction of the new railway line will link León and Asturias with a modern high-speed line, permitting both passenger and freight trains. Because of this, the line is socioeconomically very important for the territorial structure of Spain.

The works to overcome the Cantabria Mountain Range are an enormous engineering challenge, at both the European and global levels, due to the geological and morphological diversity of the mountain massif. 

European Funding

Adif AV has received aid and financing for this line from the various European Union (EU) funds and programmes.

"A way to make Europe"


Quality service

From time immemorial the Cantabrian Mountain Range has been an almost impassable obstacle between the meseta and the north of the Iberian Peninsula, historically representing a natural communication barrier between the principality and the Castile-León meseta. Opening a railway pass to and from Asturias became a priority during the second half of the 19th century.

More than 120 years have gone by since the official opening of the Puerto de Pajares railway on 15 August, 1884, by King Alfonso XII and Queen María Cristina, but the layout of the track, with several distinctive aspects, has hardly changed, including the continuous series of tunnels, the winding route, with curves that have a radius of less than 300 metres, and the steep ramps and slopes.

Commitment to the environment


Environmental protection actions are carried out throughout the work in order to ensure the railway is integrated into the environment.

In this regard, and in order to safeguard the natural richness of the territory crossed by the Pajares New Line, an environmental protection policy has been applied as one of the strategic priorities of Adif Alta Velocidad.

Planning and building a base tunnel 25 km long involves a clear commitment to minimising the environmental impact that can be caused by a high-speed railway line. The effects in this case are confined to the area around the embankments, the material resulting from the excavation and the implementation of the auxiliary systems of the works.

The most important actions in this environmental area are the following:

  • Waste control.
  • The material is carried on a conveyor belt to the controlled landfill for inert waste (DCRI) to avoid heavy lorry traffic in the area.
  • Protection of the River Huerna according to Northern Water Authority parameters.
  • Treatment and protection of hydrological systems: water purification, waste water treatment, industrial water treatment facility, flood containment tanks, redirecting and channelling towards the basins.
  • Reduction of pollutant emissions into the atmosphere.
  • Regeneration and environmental enhancement in tunnel mouth areas and DCRI.
  • Environmental integration and compensation measures in accordance with the Environmental Impact Statement: laying out of topsoil, hydro-sowing, sowing.
  • Planting of indigenous species: hazelnut trees, chestnut trees, oaks, poplars, willows, birches, lime trees, rowans, holly (main sustenance for wood grouse) and cherry trees (main sustenance for brown bears).
  • Faunal protection: partnership agreement between ADIF and the Brown Bear Foundation for the monitoring, control of conservation measures and protection of the natural habitat of the Iberian brown bear (Ursus arctos) in the construction area of the Pajares Tunnels.
  • Geological surveys respecting the Western capercaillie roosting areas.
Infrastructure characteristics
Pajares New Line.
Length of the Pajares tunnels
Pajares Tunnels Section
Length of the Pontoon Tunnel