Built in the 11th century on a former Basilica, it has undergone more expansion over the centuries, preserving original structure, which makes it one of the most important examples of Romanesque rounds in Italy. Cathedral contains important works, including a tomb by Bonino da Campione, the organ by Giangiacomo Antegnati, the marble sarcophagus by Berardo Maggi and the cycle by Moretto and Romanino canvases made for the chapel of the Most Holy Sacrament of Basilica of San Pietro de Dom and transferred here after its demolition. Of great importance is also the Crypt, dating to the 6th century but restored in the eighth century. The interior is divided into several zones placed in several levels. Characterized by sober solemnity of Romanesque architecture, it has its present appearance in the 19th century restoration work by Luigi Arcioni, which has eliminated all subsequent stratification and brought to light the original base. The Platea, central circular core, is placed at the lowest level. The Crypt below was part of former Basilica and, as such, is the oldest place of Brescia Christianity.