The cathedral was built in the Romanesque style and is one of the most unique and beautiful in Lombardy. Construction began in 1160, underwent modifications in the 16th century, and the last restoration was in 1965.

The main entrance door, flanked by two lions—one on each side—is a classic Romanesque element. Above it is a large rose window and two additional windows added during the Renaissance period. A bell tower stands to the side of the cathedral.

Inside, the cathedral features a classic three-aisled layout with numerous works of art, including statues of the city’s founders: Pompeo and Federico Barbarossa.