The patrons of Penna in Teverina are Saint Valentine, celebrated on 14 February, and the Madonna della Neve, celebrated on 5 August with a tasting of the tortiglione, the town's typical pastry. The apse of the parish church, dedicated to Santa Maria della Neve, is adorned with a 17th-century painting depicting precisely «the Madonna della Neve and Saint Valentine, patron of Penna».
The medieval village, marked by towers and gates, still retains its original layout, with characteristic little alleys and steep outdoor staircases: it is reached through the Porta Civica, which leads into the square of San Valentino where the church stands, of medieval origin and recorded from at least 1276, although nothing remains of the original building after the enlargements and renovations of the 16th and 17th centuries; the portal inscription bears the date 1651. The town was long disputed between the Orsini and Colonna families: on 7 December 1502 Gian Corrado Orsini of Mugnano, lord of Bomarzo and condottiero of the Republic of Venice, bought the castle of Penna, and on his death his son Maerbale settled there, giving rise to the complex whose famous Fonte Orsina was its greatest attraction. On the municipal coat of arms, superimposed on the Orsini family's own, is a small shield depicting a goose feather and the river Tiber, recalling the town's name.
