The crypt in the cathedral

The visitor has the opportunity to access the treasure, paying a fee. This visit truly deserves to be done, because unlike so many religious museums, all the attention is not focused only on religious vestments and objects. The crypt is a place of great suggestiveness, which reserves the visitor many emotions. The collection, the architecture and the burials are the main lines that lead one's visit. Of course, it is valuable to know a little of the history of the city to properly enjoy the visit, and the presence of a guide will surely be appreciated in this regard.

a) the collections

In fact, the magnificent Byzantine crown of Constance (see photo) is a show in itself, but the true emotion comes if one gets to its secrets, the History and the stories it narrates.
The discovery of the beautiful Frederician altar frontal deserves the same consideration. It is a masterpiece, embroidered with silver thread enriched with pearls, nacre and precious stones, within which Friedrich Hohenstaufen's eagle dominates oriental figures, probably both Muslims and Jews.
The room naturally is full of many other treasures.

b) the architecture

If the treasure room, beautiful and elegant in its proportions, is not surprising, this is not the case with the second room next to it: there is a complex architectural proposal that ranges from the Muslim past with a typical Muqarnas niche (see photo). The ceiling is that high (about 20 meters) it leaves us puzzled. Fortunately, the walls bear so many wounds they help us to make an opinion that this part of the building, in origin, was probably an outside area, which then has been included among the covered spaces.
The next room reserves the surprise of a staircase that leads into a delightful atmosphere, full of mystery to the crypt itself. It is all a lover of medieval history may wish: an underground long nave, led by an altar adorned with mosaic crosses, paving over several niches which host sarcophagi of various ages.

c) the burial (see photo)

As said before, it is better in such a place to know the history or be accompanied by a connoisseur. Beyond the visual pleasure of particularly refined sarcophagi, the strongest emotion is however given by History itself. For example, Bishop Hugh's sarcophagus reminds us he is the one who brought the remains of Holy Cristina in Palermo; the sarcophagus then of famous cardinal Gianettino Doria, the skilled Genoese who gave life to the cult of Holy  Rosalia, considered the saver of the city during the plague years 1620's.
How not feel moved staring at Frederick of Antioch's gisant? he is the illegitimate son of Emperor Friedrich II, and became a great ruler of Antioch Latin principality in Syria, by the way created by Italian-Norman Bohemond Altavilla. Emotion again if you realise that Frederick rests so close to his family, which still today lives in the same palace he built, and which is one of the most impressive visit Palermo offers to its visitors
Not to mention then the figure of Walter of the Mill, the most significant Bishop in the Norman period, remarkable for his skill but deplorable for his lust for power and the constant intrigue without scruples.
In my opinion (which is also Julius Norwich's one), he is the main responsible for the Norman failure in Sicily.