Heralded by the impressive Romanesque bell tower and the magnificent central portal, Rieti Cathedral, dedicated to St Mary of the Assumption, was founded in the 13th century on the site of an early Christian basilica documented as early as the 5th century.
The complex was remodelled several times, first in the 15th century and then between the 17th and 19th centuries. It comprises the upper church, the crypt and the baptistery (13th century). The Baroque interior, in the shape of a Latin cross with three naves, features notable chapels, including that of St Barbara, with a statue of the saint, a work from 1657 by Giannantonio Mari based on a design by Gian Lorenzo Bernini. At the end of the nave is the elegant Chapel of the Sacrament, adorned with stucco work by Gregorio Grimani da Stroncone (1635–37) and frescoes by V. Vanenti. The crypt is medieval, with columns salvaged from the Roman city and, on the walls, what remains of 14th-century frescoes.