None of the breakaways have made it to the finish yet, with the sprinters dominating the honours so far. Stage 5 takes the contenders to the Massif Central ski resort of Le Lioran, and the 216 km is likely to shake up the Tour de France.
Some believe this stage could favour the risk-takers willing to push the pain barrier and set out for victory in a small group.
Organiser have looked to change the race route in recent years and an early visit to the Massif Central allowed them to include an extra range of mountains before the Pyrenees and Alps.
The first mountain stage usually takes place later in the race, around the second week. But this year, racers will have to be ready now to show their physical strength.
But it won't just be the breakaway specialists eying Wednesday's fifth stage, it's also ideally suited to a puncher -- those riders who excel in hilly one-day classics.
"I think it's a bit too early to see a real GC battle but it's definitely somewhere where there will be time gaps," said the Sky team leader, Chris Froome.