St. Nicholas is the main church, originally dedicated to the Virgin, and perhaps the town was formed precisely around this building. The original building dates back to the Middle Ages, to the 800s, when the Saracens raids led the people to take refuge in high and defensible places. It is cited in a papal bull of 1213 by Pope Innocent III and certainly had a look very different from now. In fact, for many centuries improvements and embellishments were made. Eventually in 1500 the side chapel of San Gregorio was built. At the beginning of 1700 the bishop ordered the town to raise the bell tower and to fuse the bell of the clock tower. In 1785, then, the inside of the church has been totally rebuilt and in 1897 the new façade was completed.