The basilica was built between the twelfth and sixteenth centuries and maintains valuable works like the wooden choir drawings made by Lorenzo Lotto. The church was opened in the Piazza del Duomo. The main front entrance was not originally connected to the episcopal palace. The exterior of the basilica retains the original Lombard-Romanesque architectural style. The temple is accessible by two entrances: The Giovanni da Campione (1353) and the Fontana della porta Isabello. The interior retains the original floor plan of a Greek cross, with a nave and two aisles further divided by pilasters that culminate in an apse.