The Tour de France is the most famous and prestigious road bicycle race in the world. Huge crowds watch hundreds of cyclists, competing from all over the world, as they race madly across the countryside over a period of twenty-six days. The race has been held every year since 1903, except for during World War I and II. Most stages of the race take place in France though there are some parts that pass through Italy, Spain, Switzerland, Belgium, Luxembourg, Germany, the Netherlands, the Republic of Ireland, and the United Kingdom.

The itinerary of the race changes each year and alternates between a clockwise and an anti-clockwise direction around France. That is, sometimes the Tour goes in a clockwise direction, visiting the Alpes first and then the Pyrenees, then the next year those two mountain ranges are visited in the reverse order. Some of the places, especially mountains and passes, are included almost annually and are famous on their own. The most famous mountains are those in the hors-catégorie (peaks where the difficulty in climbing is "beyond categorization"), including the Col du Tourmalet which is one of the most famous climbs in the race. The Tourmalet has been included more often than any other mountain pass, beginning in 1910 when the Pyrenees were first included in the race. Tourmalet is also the name of a cheese made from sheep's milk produced in these mountains.

The tough climb of Alpe d'Huez is another favorite one, as well as the climb at Mont Ventoux, which is often claimed to be the hardest climb in the Tour because of the harsh conditions there. Alpe d'Huez is in the Central French Alps and is 6,069 feet high.

The Tour is popular in France, not only as a sporting event but also as a matter of national identity and pride. Millions of spectators line the route to see the Tour, some of them having camped a week in advance to get the best views. Just before the riders pass through any given town, the fans begin to pack the sides of the road until they are often just an arm's length from the riders.

Even if the crowds are wild, the riders have an unwritten code of conduct: whenever possible, they allow a rider to lead when the race passes through his home village or on his birthday