Tunnel du Mortier

Useful Information

Location: On the road D218 between Mortier and Autrans. Best accessed from Autrans.
Open: No restrictions.
Fee: free.
Classification: SubterraneaTunnel
Light: bring torch
Dimension: L=500 m, A=1,400 m asl.
Guided tours:
Address: Tunnel du Mortier.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


1968 built for the Winter Olympics in Grenoble.
20-APR-1992 .


The Tunnel du Mortier is a road tunnel on the D218 between Mortier and Autrans. The road and tunnel was built in 1968 for the Olympic Winter Games in Grenoble and was closed in 1992 after a rockfall which destroyed the road. As this road is of little importance and the possibility of another rockfall is very high the gornment decided not to repair the road. It was closed and is now used by hikers and mountain bikers. The tunnel is closed for the traffic and was partly blocked by a dam of earth on the eastern side.

The Isère river forms a wide valley with a flat floor about 190 m asl, where the city Grenoble is located. From Grenoble the river flows to the northwest and turns to the southwest near Voreppe. The mountain ridges in this river knee are the northern tip of the Vercors massiv, consisting of limestone and forming impressive cliffs. The small town Mortier or Montaud is located on a plateau on this tip which is around 900 asl. Two roads connect the village with the valley, the D3 from Veurey-Voroize and the D218 from Saint-Quentin-sur-Isère. The D218 continues to the south, a narrow and winding road leading up to the foot of the limestone cliffs named la Buffe. At a height of about 1,400 m asl the 500 m long tunnel crosses the ridge, and reappears in the valley of Autrans. The road leads down the valley to Autrans, which is around 1,050 m asl.

So why is this abandoned road tunnel an interesting tourist destination? We think its the extraordinary location, cutting through the northern limestone cliffs of the Vercors, which look like the bow of a ship. It is possible to drive to the tunnel from Autrans and to walk both through the tunnel and also uphill to the edge of the escarpment.