Highest point: 1,753m
It's the Tour's longest day, 237.5 kilometres from Carcassonne to the Haute- Garonne and the town at the foot of the Pyrenees. The stage is a breakaway's dream for any number of reasons: it's the day after a repose in Carcassonne, the real Pyrenean mountains are still to come, and it's as lumpy as anything.
Four minor category climbs will pass under the wheels until the HC-ranked Port de Balès arrives after 204km. It was here that Andy Schleck's notorious, haplessly resolved mechanical occurred in 2010, causing him to lose the yellow jersey amidst the rumble of 'chaingate'.
The isolated climb from the north side on the narrow road has some viciously steep sections in the middle and if any adventurers make it over the top with 35-40 seconds over the peloton,the very rapid and technical descent should mean there's enough slack to allow them to contest the win in the spa town below.
Thomas Voeckler has won twice here, in 2010 and 2012. On the latter occasion he pulled on the polka dot jersey, which he kept all the way to Paris. French riders will probably pack the breakaway and perhaps a worthy successor to Voeckler will take over – FDJ's Arthur Vichot maybe.
Haimar Zubeldia says... "The Porte de Balès is a hard, hard climb and the first part of the descent is tricky. It's one of those rare days this Tour where a super descender such as Nibali might try to attack on the climb to go full gas on the descent. A hard day to control tactically."
At 152km, the race passes over the oft used cat 2 Portet d'Aspet and it's a fair chance the first rider over will be French. The climb has featured nine times since 2001 and on only one occasion has the rider been from outside of France – Dutchman Erik Dekker in 2005. The descent of the Portet d'Aspet is where Fabio Casartelli died in 1995 after a crash in which he hit his head on the roadside concrete blocks.