The Mont Blanc Tunnel is a highway tunnel in Europe, under the Mont Blanc mountain in the Alps. It links Chamonix, Haute-Savoie, France with Courmayeur, Aosta Valley, Italy, via European route E25, in particular the motorway from Geneva to Turin. The passageway is one of the major trans-Alpine transport routes, particularly for Italy, which relies on this tunnel for transporting as much as one-third of its freight to northern Europe. It reduces the route from France to Turin by 50 kilometres and to Milan by 100 km. Northeast of Mont Blanc's summit, the tunnel is about 15 km southwest of the tripoint with Switzerland, near Mont Dolent.
Begun in 1957 and completed in 1965, the tunnel is 11.611 km in length, 8.6 m in width, and 4.35 m in height. The passageway is not horizontal, but in a slightly inverted "V", which assists ventilation.
Wikipedia https://en.wikipedia.org/wiki/Mont_Blanc_Tunnel
Official Website http://www.tunnelmb.net/
Coordinates 45°52'27.556" N 6°53'30.32" E