The town is located in the northern part of the Tuscia area of Viterbo near the Tuscan border, and it affords a magnificent view of Mount Amiata and the solitary outposts of Castell'Azzara, Radicofani and Torre Alfina.

The fortress was restored and fortified during the papacy of Hadrian IV. This rectangular estate has three towers that are united by a crenellated outer wall. The Gothic church of San Martino preserves three frescoes dating to the fourteenth-fifteenth century and attributed to the school of Pietro Lorenzetti. The parish church of Santissimo Salvatore has several fourteenth-century frescoes, an eighteenth-century painting (Martyrdom of St. Sebastian) and a wooden statue of St. Rocco. Palazzo Sforza, dating to 1537, boasts of a grand and austere portal with rounded ashlar work. Inside, there are several frescoes from the Mannerist school. In the open countryside not far from town, we can admire the little church of Madonna del Giglio, built during the first half of the sixteenth century over a previous fourteenth-century aedicule. On the walls, there are fragments of frescoes done by the Zuccari school. The village of Centeno is located near Proceno. It was the site of the pontifical customs house until l870. In 1625, Galileo Galilei stayed there for about 20 days on his way to Rome to go before the Holy Office.