 There are forbidding and barren scree slopes with protruding pinnacles of weathered rock on the upper south side.Known as the Casse Déserte, this area has formed a dramatic backdrop to some key moments in the Tour de France, and often featured in iconic 1950s black-and-white photos of the race.From the south, the climb starts at Guillestre from where it is in length, at an average gradient of 4.8%.