This auditorium is the oldest building in town. Formerly it was the ancient church of Sperlonga and took the name of Sanctae Mariae de Spelonche. The presence of this church seems to date back to the 12th century as Codex Caietanus is mentioned as an important document of the time.
It was initially built on two small naves but other rooms have been added over the decades. Of great importance are the frescoes dating back to the XII century found in one of the chapels. They depict in the lower register San Cosma, San Saba and the remains of an ascension of the Virgin and in the upper register the Madonna Odigitria venerated in Constantinople and by pilgrim monks in southern Italy.