The patron saint of Pontremoli, whose liturgical memory recurs on 31 January, is solemnly celebrated at his eponymous church with a series of eucharistic rituals in the morning; further rites in the afternoon are presided over by the Bishop. Before this, however, a traditional three-day observance is held. At the end of the festival, on the evening of 31 January, a bonfire is lit on the banks of the River Verde, making for an involving, breathtaking conclusion. 

Source: duomodipontremoli.it