In this video, courtesy of TeamSky.com, Froome predicts that the second stage in particular could catch some riders by surprise.
"I think we're in for some tough racing," he said. "If people haven't seen it it might catch a few people off guard. [They are] pretty tricky roads, a lot of narrow, quite windy, undulating roads - especially for the first two stages where everyone is nervous, and everyone has a chance to be in yellow."
"Everyone is going to come in on the first few days in great shape, and it's going to be exciting to watch, but for us in the peloton it's going to be stressful," Porte said.