Mont Blanc Tunnel (French portal)

The Mont Blanc Tunnel is a road tunnel in the Alps under the Mont Blanc mountain, linking Chamonix, Haute-Savoie, France, and Courmayeur, Aosta Valley, Italy. It is one of the major trans-Alpine transport routes, particularly for Italy, which relies on the tunnel for transporting as much as one-third of its freight to northern Europe. It reduces the route from France to Turin by 50 km and to Milan by 100 km.

Begun in 1957 and completed in 1965, the Mont Blanc Tunnel is 11.6 kilometres (7.25 miles) long, 8.6 metres (28.2 ft) wide, and 4.35 metres (14.3 ft) high. The tunnel is not horizontal, but in a slightly inverted "V". Altitude on the French side: 1274 m (4091 ft); Italian side: 1381 m (4530 ft). The tunnel consists of a single gallery with a two-lane dual direction road.