Saint Septimus cathedral is the main place of worship of Jesi. In 1208, under Bishop Dago, the construction of a new cathedral was started, in a style of transition from Romanesque to Gothic to three naves. In 1227 the architect Giorgio da Como puts his hand to the façade, with a protire supported by columns resting on the back of two lion stylists in Red Marble of Verona, still preserved inside the Duomo as an aqueduct. It was completed in 1238. During the 16th and 17th centuries, the church was enriched with works by local artists Antonino Sarti and Filippo Bellini, who painted respectively the Death of Saint Septimius in 1617 and St. John the Baptist. Bishop Ghislieri also made the baptismal bathtub in Rosso di Verona and commissioned the burial of Bishop Ripanti, to Giovanni di Gabriele da Como. In 1732 Bishop Fonseca, taken from that renewal, demolished the old cathedral to reconstruct it according to the design of Roman architect Filippo Barrigioni. The new building, completed in 1741, featured a large single-dome with a hemispherical dome. The four dome plumes were frescoed by Carlo Paolucci of Urbino and Placido Lazzarini of Pesaro in 1785. The artist Jessel Domenico Valeri draws the choir, then carved in Walnut by Marco Baroncio. The façade is on a hut and was completed in 1889, by Gaetano Morichini. It has a masonry wall in red and travertine bricks and is divided into two bands. In the lower end, the portal is located in the center, with modern bronze facades, characterized by a shallow prothium consisting of a triangular tympanum supported by two corinthian columns. On the sides, each inside a niche, there are the statues of San Marcello I and San Settimio. On the left of the building, in the back position, is the bell tower. It was built between 1782 and 1784 by Jesuit Francesco Matellicani. It has a square plant, it is brick, and ends with a slender cupola. The interior of St. Septimus cathedral features a Latin cross-shaped plant, with a single nave, side by side with six chapels, three on each side, shallow transept and semicircular apse. The nave is covered with lunetted barrel vault and illuminated by rectangular windows ; in the center of the vault, there is a canvas depicting the Annunciation. The side chapels are rectangular, illuminated by bezel windows and bordered by a marble balustrade. In the first chapel on the left is the valuable 16th-century baptismal font in Verona's red marble, dating back to 15th century marble lilies. At the third altar, the blade of San Biagio, which repairs the son of the widow of Giovanni Odazzi; in the right arm of the presbytery the martyrdom of St. Lawrence of Gaetano Lapis, circa 1745; on the opposite side is the great canvas of Cristoforo Unterperger with the Communion of the Apostles near the Renaissance sepulcher of Angelo Ripanti of 1512. They follow a Madonna with Child and two saints in the manner of Sebastiano Conca of the second half of the eighteenth century the Preaching of the Baptist by Philip Bellini, and a Madonna with a Child. On the left side of the nave, there is the baroque pulpit. The deep semicircular apse is entirely occupied by the presbytery, raised by a few steps to the rest of the church. In the center, there is the Baroque altar in polychrome marbles, and in the advanced position there is the white marble ambone, with the sculpted bas-reliefs of the symbols of the Evangelists. In the basin of the apse, there are carved 18th-century carved wooden stalls, arranged on two levels, high relief with the Madonna of Loreto, and two organs with beautiful rococo boxes. The basin was frescoed by Biagio Biagetti in 1937 with the Redeemer on the throne between Saints. The two great rococo wooded armours are fitted with organs.