Some of the most famous cycling tours include: 1. Tour de France: The most prestigious and well-known professional cycling race held annually in France. 2. Giro d'Italia: A major professional cycling stage race held in Italy, considered one of the three Grand Tours alongside the Tour de France and Vuelta a España. 3. Vuelta a España: Another Grand Tour, held in Spain, featuring a three-week race across several challenging stages. 4. Tour de Suisse: A multi-stage cycling race in Switzerland, attracting top riders and offering stunning mountainous routes. 5. Tour of California: A professional cycling race held in California, USA, featuring diverse terrains and attracting top riders from around the world. 6. Paris-Roubaix: A one-day classic race held in France, famous for its rough cobblestone sections that provide a unique and challenging experience. 7. Tour Down Under: The first race on the UCI World Tour calendar, held in Australia, is often favored by professional teams as a warm-up before the European season. 8. Amstel Gold Race: A classic one-day race held in the Netherlands, known for its steep hills and challenging parcours. 9. Liège-Bastogne-Liège: One of the oldest and most prestigious one-day races in the cycling calendar, held in Belgium and known for its demanding hilly route. 10. Tour de Romandie: A six-day stage race held in Switzerland, often considered as an important preparation race for the Giro d'Italia or Tour de France. These are just a few examples, and there are numerous other famous cycling tours and races held across the world, each with its own unique characteristics and challenges.