Which major cycling event was set to pass through the Vatican for the first…

Concept: Professional road cycling's three Grand Tours are three-week stage races, and each is anchored to a host nation whose territory the route is drawn across — the Giro d'Italia in Italy, the Tour de France in France and the Vuelta a España in Spain. Vatican City is a sovereign enclave of about 0.44 square kilometres lying entirely inside the city of Rome, so a bicycle race can cross it only when its course already runs through Rome and the Vatican authorities open the territory to it.

Application: The Giro d'Italia is the Italian Grand Tour, and its 2025 edition closed on 1 June 2025 with a circuit stage in Rome. For the Catholic Jubilee Year of 2025 the organisers routed that closing circuit through Vatican City, where Pope Leo XIV greeted the riders — the first time the race passed through Vatican territory.

Cross-check: None of the other races listed is staged anywhere near Rome:

• Vuelta a España — Spain's Grand Tour, held from late August into September across the Iberian Peninsula.

• Tour de France — France's Grand Tour, held each July across France and its bordering countries.

• Tour Down Under — Australia's one-week WorldTour race, held each January around Adelaide in South Australia.

Hence the major cycling event set to pass through the Vatican for the first time in 2025 was the Giro d'Italia.