Skip to main content

Tunnels of France

Railways, roads and even canals, France is home to many underground engineering feats.

France is home to over 60 tunnels of over 1,000m in length, four of those are over 10,000m in length and are often sited as modern engineering marvels. 

We've compiled a list of the most impressive tunnels from the ground-breaking Channel Tunnel to the Mount Blanc Tunnel, an architectural feat.

Road Tunnels

Fréjus Road Tunnel

Length: 12.87 km • Road: RN543/Traforo T4/European Route E70 • Region: Auvergne-Rhône-Alpes • Construction started: 1974 • Complete: 1980 • Cost: 2 billion Francs (equivalent to £624m, adjusted to inflation) • Links: Modane, France with Bardonecchia, Italy

The the mid-1970s it was apparent that the then twenty year old Mont Blanc Tunnel just wasn't built to accommodate the increasing numbers of vehicles driving between France and Italy, a new route was needed to ease congestion and so came about the Fréjus Road tunnel.

Built parallel to the now redundant Fréjus Rail tunnel, it successfully levelled traffic numbers and took the strain off the Mont Blanc tunnel. 

Following the 1999 Mont Blanc fire, the tunnel, like many other road tunnels across France and its neighbouring countries, implemented new and up-to-date safety measures.

Mont Blanc Tunnel portal in France by Kristoferb - Own work, CC BY-SA 3.0
Mont Blanc Tunnel portal in France by Kristoferb - Own work, CC BY-SA 3.0

Mont Blanc Tunnel

Length: 11.61 km • Road: RN205/Traforo T1/European Route E25 • Region: Auvergne-Rhône-Alpes • Construction started: 1959 • Complete: 1965 • Links: Chamonix, France with Courmayeur, Italy

Formerly holder of the the 'Longest Road Tunnel in the World' title from 1959 - 1978, the Mont Blanc tunnel was one of the great engineering and architectural feats of the twentieth century.

After the French and Italian governments reached an agreement on the tunnel in 1949, a workforce of over 350 began boring in 1959 and 700 tonnes of explosives and six years later, the tunnel opened to the public.

In 1999 the tunnel suffered a major fire after a truck carrying flour and margarine caught fire 2km into the tunnel. The resulting thick black smoke leading to low oxygen levels and lack of safety procedures at the time led to 37 people being killed. It led to a major safety overhaul of tunnels across Europe.

Rail tunnels

Channel Tunnel

Length: 50.45 km • Route: HS1/LGV Nord high-speed line • Region: Pas-de-Calais • Construction started: 1988 • Complete: 1994 • Cost: €16.2 billion (equivalent to £14.5 billion, adjusted to inflation) • Links: Coquelles, France with Folkestone, UK

Although no longer the world's longest rail tunnel (overtaken by the Gotthard Base Tunnel in Switzerland in 2016), it does still hold the titles of 'Longest Underwater Section of a Tunnel' and 'Longest International Tunnel' and is seen as the biggest engineering feat of the twentieth century

The idea of a cross channel tunnel wasn't new. The concept was put forward as early as 1802 but the project wasn't realised until 1988 when tunnelling began on the French side. The famous handshake between the French and the British happened in 1990 when the two boring operations finally met in the middle 75m below the seabed.

The tunnel was formally opened by then-President Mitterrand and Queen Elizabeth II and rail operations began soon after. Since its opening more than 10 billion passengers have travelled through the tunnel between France and the UK.

Canal tunnels

Rove Tunnel

Length: 7,120m • Waterway: Canal de Marseille au Rhône • Region: Provence-Alpes-Côte-d-Azur • Construction started: 1906 • Opened: 1927

The Rove Tunnel was a major work of civil engineering upon completion in the late 1920s. When it was built, along with the construction of the Canal du Marseille au Rhône in the early twentieth century, it was the longest tunnel of its kind in France but its success was short-lived. After a catastrophic collapse in 1963 the tunnel was closed. The canal then became a redundant route and closed shortly after although it does still remain today.

Malpas Tunnel

Length: 165m • Waterway: Canal du Midi • Region: Occitanie • Excavated: 1679

Hailed as Europe's first navigable canal tunnel, the Malpas tunnel was bored by hand in 1679 and took less than a month to complete under the direction of chief engineer Pierre-Paul Riquet. Just 12 years prior in 1667, construction of the Canal du Midi had begun and the tunnel provided a suitable passage through the hill of Hérault. 

The site was also home to another tunnel (below the Malpas tunnel) dug in the middle ages to drain the nearby Étang de Montady, a former freshwater wetland and later on, in the nineteenth century yet another tunnel constructed (above the Malpas tunnel).

Rove Tunnel in 1929
Rove Tunnel in 1929