The building introduces him in the dress acquired in the second destination' of the XVIII century, when it was' built the beautiful opened staircase, but it still preserves some medieval structures, of exceptional importance, risalenti to the second destination' of the XI century, that is' during the restructuring operated by the bishop Erveo. It deals with a series of building tarsie policrome that is developed along the southern front, of various ground floor environments and of the above Palatine Chapel, whose turned they are straight from columns of bare.