One of Italy's most celebrated holidays is 25 April, the Festa della Liberazione, or Liberation Day.
The day marks the liberation of the Bel Paese by Allied troops in World War II and is celebrated throughout the peninsula with parades, concerts, demonstrations, speeches, and more. Among the honoured are soldiers, victims of Nazi bombings and occupations, and especially partisans in the Italian Resistance.
From large marches in cities to intimate gatherings in small squares, just about every town in Italy does something for Liberation Day; one thing you're likely to hear somewhere on 25 April is "Bella Ciao," the simple folk song that tells the tale of a partisan who died for freedom, asking only to buried in the mountains under the shadow of a beautiful flower.
Hear "Bella Ciao" and see some footage of past Liberation Day festivities around Italy:
Note that the 25th of April is a "red day" on Italian calendars, which means it's an official holiday and most everything is closed, including public offices and even some restaurants and public transportation--all the more excuse to take in the festivities.