Timeline

Heritage classified

Key figures

Origin and history

The Somport railway tunnel, 7,874 metres long (including 3,160 metres in France), was dug between 1908 and 1915 to connect Pau to Canfranc. The work, conducted 24 hours a day with drills and dynamite, encountered challenges such as a flood in 1911. The Franco-Spanish junction was completed in October 1912, and the tunnel opened in 1915, with a boundary materialized by two stone terminals.

The railway line was officially opened in 1928 after the completion of the Canfranc International Station, inaugurated by Louis Barthou, Minister of Public Works. However, a derailment in 1970 destroyed the Estanguet bridge, resulting in a definitive stoppage of traffic. Since then, the tunnel has served as a back-up to the Somport road tunnel, which opened in 2003.

Ranked a historic monument in 1984, the tunnel also housed from 1986 an underground laboratory dedicated to nuclear physics, studying black matter and neutrinos. In 2012, a symbolic centenary was celebrated by the presidents of Aquitaine and Aragon, relaunching discussions on a reopening. In 2016, the two regions reaffirmed this commitment, and in 2024 a study estimated the cost of rehabilitation for 52 months at EUR 93 million.

On the Spanish side, a French bas-relief was partially withdrawn in 2019, replacing the eagle of Saint John with the heraldic lions, in a context of symbolic re-appropriation. The tunnel, owned by the French state, remains a cross-border issue, combining industrial heritage, historical memory and contemporary debates on sustainable mobility.

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