The square, also known as the ancient 'platea canape', holds the parish church of Santa Maria Infraportas, which in ancient documents is called 'foris portam', meaning beyond the public gate of Santa Maria. According to the tradition, the apostles Peter and Paul celebrated the mysteries there, in the current chapel of the Assumption. The church is rich in votive entries: the entrance is protected by a small portico with three round arches supported by four columns with Romanesque capitals. On the other side, there is Palazzo degli Atti (14th century). The square is closed by the Church of San Domenico with an annexed convent. The bull of Honorius IV dates back to 1285 and authorized the supposed construction of the church in the same year. The façade has a beautiful gothic portal and the interior features frescoes from the 1400s. The later church was converted into an auditorium to a design by architect Franco Antonelli. In Via Santa Caterina, adjacent to the square, there is a church with the same name, characterized by a pointed arched portal and a round window from the 14th century.
