At 1489m and an average gradient of 6.5 per cent, the Col d' Aspin is rarely the site of a summit finish. However, it is nonetheless a key climb in the notorious 'Circle of Death' stage route that encompasses the Col de Peyresourde, this climb, the Col d'Aubisque and the Col du Tourmalet. It's often cited as a favourite climb by many riders. However, it was an explosive attack by one Ricardo Ricco on 11 July 2008 that netted the disgraced climber the stage win and earned the climb a somewhat notorious reputation.
The stage that day ended in Bagnere-de-Bigorre, with Col d'Aspin the final climb. Ricco's team-mate Leonardo Piepolli had launched an earlier attack: when he was caught by the leaders, Ricco exploded away five kilometres from the summit and stayed away on the descent to take the win.
His victory was short lived, however, as only six days later he tested positive for EPO and was removed from the race. He returned to the sport in 2010, but was banned for 12 years in 2012 after becoming embroiled in another doping scandal.
Col du Tourmalet
The Col du Tourmalet will always occupy a special place in Tour history as the first ever mountain pass the Tour traversed in 1910. The 2015 Tour will mark the 77th ascent of the Tourmalet. It has been the site of a summit finish twice in its history: once in 1974 and then again in 2010, when Alberto Contador and Andy Schleck paced each other to the finish line.
The Tourmalet has acted as a launchpad for many successful attacks, but posible the most dramatic was Bernard Hinault's attack on its slopes in the 1986 Tour. Hinault had pledged to support his teammate Greg LeMond's bid for the yellow jersey in return for LeMond's support for Hinault's fifth victory the year before: however, Hinault had attacked LeMond the day before and took the yellow jersey with a five-minute lead.
The Tourmalet was the first climb of the 13th stage, and Hinault attacked again - gaining three minutes by the start of the next climb (the Col d'Aspin). However, Hinault had misjudged his effort and was eventually overhauled - putting LeMond back within reach of the yellow jersey and setting the scene for a titanic battle between the two riders.
Plateau de Beille
A relatively recent addition to the Pyrenean pantheon, Plateau de Beille is a savage climb with an average gradient of 7.9 per cent over 15.9km. Because of this, it's been a summit finish on each of its five appearances, and the sixth ascent on Stage 12 of the 2015 Tour is no different.
Marco Pantani - another rider with a troubled history with drugs, which ultimately claimed his life in tragic circumstances in 2004 - took the victory on the first Plateau de Beille stage finish back in 1998 on his way to victory in the Tour.
Going into the Pyrenees on this troubled Tour - which began with the Festina scandal and continued with rider protests - Pantani trailed race leader Jan Ullrich by more than five minutes. Pantani had gained 23 seconds on Ullrich on the previous stage to Luchon. When the peloton hit Plateau de Beille on Stage 11, Pantani launched a trademark solo attack to take the stage victory and claim back another 1min 40sec on Ullrich.
Pantani subsequently trounced Ullrich in the Alps, turning a three-minute deficit into a six-minute lead and becoming the seventh rider in history to achieve a Giro-Tour double. Could Alberto Contador repeat Pantani's feat this year?