Tourmalet is doubtless one of the most famous Tour de France cols.
Anyway, it is the most climbed pass in the Tour (82 times until to 2012),
thanks to the challenge it offers and its strategic position.
The ascent from the eastern side is slightly steeper
than the ascent from the western side.
After the start in Ste-Marie de Campan the first four kilometers
through the pleasant Vallée de Gripp are easy
with the slope not exceeding 5%.
Then, the road becomes steep,
which remains the case for the 12 kilometers that lie ahead up to the col.
Mostly the slope is 9% but there are some stretches of 10%.
The longest one begins in the semi-open avalanche construction
that one enters after a long serpentine into a side valley
on the cyclist's left hand side.
This 10% stretch ends in the ugly ski resort of La Mongie.
The final few kilometers up to the pass are the most beautiful
with views on grey and dark brown rough mountain faces.
The slope is typically 9% again but the last 500
meters are a bit steeper.