Le Mans Grand Prix d'Endurance (also called Le Mans 24-Hour Race)probably the world's best-known automobile race (automobile racing), run annually (with few exceptions) since 1923 at the Sarthe road-racing circuit, near Le Mans, France. Since 1928 the winner has been the car that travels the greatest distance in a 24-hour time period. The racing circuit is roughly 8.5 miles (13.6 km) long, and the race is open only to sports cars (modified cars that are built for highway driving). The race is run in June, on one of the shortest nights of the year. The Le Mans Grand Prix is sanctioned by the International Automobile Federation (FIA) and is included in the FIA's annual series of races to determine a world manufacturer's championship. (For a list of Le Mans winners, see table (Le Mans Grand Prix d'Endurance (also called Le Mans 24-Hour Race)).)