Your guide to the 2015 Tour de France cobbled stage (video)

The Tour de France returns to the cobbles for a second year running, and just like in 2014, the stage promises an early test for the overall contenders on stage four.

Organisers ASO produced a challenging first week, with the finish on the Mur de Huy on stage three followed by seven sectors of pavé. If day three paid homage to the Ardennes Classics, day four brings the cobbled Classic contenders into play.

But it's not just about the stage winner, it's about which of the overall contenders can lose the least time on the cobbles. In 2014, Vincenzo Nibali sailed over the stones on his way to third on the stage, while Chris Froome crashed out of the race before the peloton had even reached the pavé. This year Froome has the yellow jersey to protect, and he'd give anything to make it unscathed through this taxing test of skill and endurance.

Alberto Contador gave up nearly three minutes last year and might be concerned the same may happen again this time. Nairo Quintana, on the other hand, is very green when it comes to cobbles.

The Colombian may have the beating of his rivals in the mountains, but having just two days of cobbled racing under his belt in his whole career could leave him exposed.

At 221km it's also the longest stage in the three-week race and is set to be challenging both mentally and physically.

 Cycling Weekly's experts discuss the Tour de France contenders