The oldest parts of the Church of Santa Caterina, in the castle of Vallo di Nera, are from the 14th or early 15th century. The present façade is a 16th-century reconstruction.

The monastic building, which was used by Augustinian nuns, is almost entirely ruined, due to the state of neglect resulting from the suppression of the monastery decreed in 1615 by Cardinal Barberini.

Remaining inside, after several transfers, are the Mystic Marriage of St. Catherine with Saints Peter, Paul, John the Baptist and Nicholas of Tolentino, altarpieces by the Roman school of the 17th century in an ornate carved polychrome frame made by local artisans; an altarpiece from the same period painted in oils; the Madonna and Child with St. Catherine, a fragmentary fresco from the early 15th century.