Collection of the diocesan museum was started by emperor Henry II and his wife Cunigunde. They were the first to start collecting liturgical items, relics and books for the cathedral dome. Later the collection was constantly increased by patrons, but was severely damaged several times due to fire. Some of the most interesting exhibits of the museum are the mantles of Henry II and Cunigunde and attire of Pope Clement II. Here you will also find an Easter candlestick and mobile altar of the 12th century, goblets, crucifixes, an 18th century silver Madonna. It used to be taken out into the town during festive processions.