St. Cassiano's Cathedral is the result of various interventions due to serious problems of static. Between 1765 to 1781, the work was entrusted to the maximum Romagna architect of the time, Cosimo Morelli, who rebuilt the choir, the presbytery, the dome and the crypt. In the late nineteenth century it was entirely redone flooring in marble and the bell tower. It was built in 1900-1901, around the perimeter of the Cathedral, a new cobbled with the center, outside the main entrance, a large cameo commemorating the Jubilee of that year. The interior is divided into three naves, the central one is very wide, with deep side chapels. The focal point of the building is the magnificent scenery of the presbytery: two symmetrical staircases that climb from the aisles, and the other two from the middle, with a further, monumental staircase that leads down to the crypt. In the first chapel to the left it is one of the few remains of the Medieval Cathedral: the font of early sixteenth century. The other chapels are rich in works of art (Ignazio Zotti, Marco, Giacomo Zampa, Filippo Scandellari, Gottarelli) and tombs. Behind the high altar stands the canvas depicting by Pietro Tedeschi, the St. Cassiano's Martyrdom. In the crypt there are three marble urns containing the remains of Saints Cassiano, Pier Crisologo, Proietto and Maurelio, enriched with friezes and putti (1698-1704), by Giuseppe Maria Mazza, a member of the Baroque.