The patron saints of Colle di Val d'Elsa are Saint Martial and Alberto da Chiatina, celebrated on 1 July: Saint Martial's patronal feast is held in the hamlet of Gracciano dell'Elsa, where the church dedicated to him stands. Saint Martial was bishop of Limoges, in France, in the 3rd century, before travelling to visit Rome.
The town holds, according to tradition, one of the nails of Christ's crucifixion: the relic, venerated for centuries, is kept in the cathedral in a tabernacle by Domenico Rosselli and is carried in solemn procession every year, during the Feast of the Holy Nail. Colle di Val d'Elsa also holds the tower-house of Arnolfo di Cambio and the church of Sant'Agostino.
