L'arriviste said:Not sure if it's what you mean, but the Cols d'Eze and de la Madone above Nice are very popular for measuring condition and very commonly used by pros based in that area.
Thanks! It was the Madone:
Armstrong himself explains: "The Col de la Madone is a 12km climb that starts in the French village of Menton. It rises from close to sea level to 927 meters. Cyclists have long used it to test themselves. Having lived in Nice for four years, I rode it many times as well. The record of 31:30 stood for many years, until in 1999 when I broke it with a 30:47. For me, the Madone is the ultimate test. It always tells me if I'm ready - ready to ride fast and ultimately, win the Tour de France. It never fails."
the famous Col de la Madone - used regularly by the great Tony Rominger, made famous by the even greater Lance Armstrong, and ridden the fastest by the slight shouldered climbing enigma, Tom Danielson (30:24).
Now I just need to find the article that links his time in Nice to Doping, the Madone and his eventual decision to leave France for Spain, for 'tax reasons.'