Second longest tunnels built in Spain

The Pajares tunnels are part of the Madrid - Asturias High Speed Line, and construction work on these tunnels was carried out between 2004 and 2009. This infrastructure crosses the Cantabrian mountain range from the municipality of Pola de Gordón (León) to Telledo (Asturias).

They are the second longest built in Spain, the sixth longest in Europe and the thirteenth longest in the world. The project was completed in March 2009.

The project consisted of the construction of twin tunnels 8.50 m in diameter and 10.67 km long, of which 7.67 km were excavated using TBMs and the remaining 3 km using conventional methods. The gradient of the tunnels is 1.685% downwards from León towards Asturias.


In addition, an intermediate access gallery of 2,045 m and 28 connecting galleries were constructed between the two tunnels with a total length of 1,262 m.


  • Location: León - Asturias, Spain.
  • Contract type: Construction.
  • Infrastructure: Construction of twin tunnels with a diameter of 8.5 m and a length of 10.67 km, of which 7.67 km were excavated using tunnel boring machines, and 3 km using conventional methods.
  • Year of project completion: 2009

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