Tour de France, Giro d'Italia, and Vuelta a España.

Major cycling races are some of the most popular and prestigious sports events in the world. They attract millions of spectators both on-site and online, and their significance and history in cycling are unmatched. There are several major cycling races around the world, but the three most well-known and respected are the Tour de France, Giro d'Italia, and Vuelta a España.

The Tour de France is the most famous of all cycling races and has been held annually since 1903. The race spans three weeks and covers over 3,500 kilometers throughout France and neighboring countries. The Tour de France is known for its dramatic mountain stages and intense sprint finishes and has been home to some of cycling's most iconic moments and athletes.

The Giro d'Italia, also known as "the Giro," was first held in 1909 and is Italy's answer to the Tour de France. The race lasts three weeks and covers over 3,400 kilometers throughout Italy. The Giro is known for its challenging mountain passes and its colorful atmosphere that celebrates Italy's rich culture and history.

The Vuelta a España, also known as "La Vuelta," is Spain's premier cycling race and has been held since 1935. The race also lasts three weeks and covers over 3,200 kilometers throughout Spain. La Vuelta is known for its strong mountain passes and for being an important race for top riders to prepare for the World Championships and Olympics.

These major cycling races attract some of the best riders in the world and are known for their high intensity and dramatic moments. They are also important for the history and development of cycling and have become a major part of the global sports calendar.