The Cathedral has three levels: the deeper level dated on VI century a. C. is an ancient palaeochristian Basilica and it is possible to admire the mosaic floor representing peacocks and ivy grasses .
Than there is an early Middle Ages church that is the enlargement of the previous church.
The Cathedral, built between XII and XIII centuries with the crypt,it'is dedicated to Saint Valentino and to the Vergine Immacolata.
The most important artistic attraction is the ambon of 1229 of Nicolaus Magister.
according to one of the various interpretations behind the ambon there is probably an Hoheustaufen family portrait.
The descendent of this family is the “stupor mundi” Federico II.
In the Cathedral it is possible to admire a rich representation of Middle Ages animals, that is present outside on the main door and inside on the capitals of the columns.
Among the fantasy animals, the most spectacular is the magnificent mosaic of the Griffin realized in the XI century with white, red black and grey strips and coloured marble.
