The Franciscan monastery of St. John the Baptist, a short distance from Celleno Vecchio, was built in 1610 around the Romanesque parish church of St. John, which still preserves its 12th-century apse (a semicircular, or polygonal, niche-shaped space attached to a basilica, church, cathedral or temple). The original nucleus is organized around a simple but richly decorated quadrangular cloister with a cycle of frescoes depicting the stories of St. Francis. Around the cloister are the cells of the brothers and in the center is a monumental puteal cistern used for collecting rainwater. The valuable frescoes in the chapel (late 15th-early 16th century) and the sacristy, as well as the 18th-century wooden choir in the apse of the church, deserve special mention.
The monastery was first transformed in 1754 and then in 1769, with the extension of the residential wing and the addition of a portico on the road side. Inside the walls there is a beautiful park of ancient holm oaks. At the beginning of the 80s, after radical restoration works, the monastery became a tourist-cultural centre, with conference and congress halls, a library and rooms for hospitality purposes.