This stage is relentless climbing, with the second highest total of the race at 4,640m through the day. The first part rises steadily to what will later be the finish at Aprica. Then comes the hard Santa Cristina, where in 1994 Miguel Induráin suffered hunger knock during a long-range attack with Marco Pantani and lost the chance for a third consecutive Giro title.
On this stage they will continue to the brutally hard Mortirolo that will split the lead group to pieces. Its gradient is slightly less tortuous than that of the Zoncolan – 10.3 against 11.9 per cent average – but it's 2.7km longer and relentless. The tricky descent leads to a steep ramp 15km from the finish that's perfect for a late attack.
Procycling's favourite to win:
Ivan Basso destroyed his rivals on stages like this in 2006, but since returning from his ban has yet to rediscover that form. Does the Liquigas leader still have the ability to win on days like this?
"Grappa, Zoncolan, Plan de Corones, Mortirolo… I don't think I want to talk about this Giro any more, let alone ride it! Cazzo, it's going to be a bloodbath! The Mortirolo is a horror, absolutely interminable. If anyone's still alive, the riders who get over the Mortirolo first should then pull away on the final climb up to Aprica, as they always do."
Flashback: Cima Pantani
Tree-covered almost to its summit, the Mortirolo is impossible to pick out from a distance. Likewise, heading up the Adda valley you would be forgiven for missing the right turn in Mazzo di Valtellina. It looks more like an insignificant lane towards remote mountain retreats than the start of a climb that Lance Armstrong declared in 2004 was the toughest he'd ever ridden.
The first rider over the Mortirolo on its Giro debut in 1990 was Leonardo Sierra. Four years on, Marco Pantani introduced himself by beating Miguel Induráin and Evgeni Berzin there. After his death in 2004, the climb was dubbed the Cima Pantani, with a special prize for the first rider to its summit. Two years later, a monument to the Italian was unveiled 8km up the climb. Pantani still holds the record at 42 minutes.
Vertical climb: 4,640m
Highest point: 1,854m
Terrain: High mountain
Category: Road Stage