Le Circuit de la Sarthe has changed significantly since the race 's conception by the Automobile Club de l'Ouest ( ACO ) in 1921 .
Le Circuit de la Sarthe is the track used for the 24 Hours of Le Mans race .
Le Circuit de la Sarthe , the track used for the 24 Hours of Le Mans race , has changed significantly since the race 's conception by the Automobile Club de l'Ouest ( ACO ) in 1921 .