Castel Sant'Angelo is one of Rome's most symbolic monuments, both for its ancient history and for its logistic position. It is closely linked to the affairs of the city, it has served as an imposing tomb suggesting the grandeur of the Roman empire, a defensive stronghold against the Barbarians and rioters, a magnificent residence and fortress at the same time for the Papal members, a dark and gloomy prison.
The castle today is the fruit of vast modifications and layers that profoundly altered the original form and structure, and it is not simple to understand its path, made more inextricable by the numerous spaces, ramps, corridors, courtyards, terraces, stairways, large and small rooms, and chapels, which follow one after the other in a connecting labyrinth. The appeal of the Museo Nazionale di Castel Sant'Angelo comes from this as well, as a continuing discovery of different environments, from the suggestive ramp once walked by the funerary court to the renaissance courtyard, from the dismal prisons to the splendid frescoed rooms, from the funerary cell to the terrace that opens a panoramic view of Rome.

The Passetto di Borgo is an elevated passageway some 800 metres in length that passes evocatively above the bustle of the everyday world as it runs along the top of the walls that used to surround and protect the Leonine city, connecting the Castle to the palaces in the Vatican. The walkway was added to the wall so that the Popes could reach their private apartments in the Castle without descending to street level, but more importantly so that they could escape from the Vatican in case of impending danger. The first time it was used was by Pope Nicholas III (1277-80), whose namesake Nicholas V upgraded it when he had the whole area of the Borgo rearranged and also created the Papal apartments inside the Castle. The Passetto became of strategic importance during the Sack of Rome in 1527, when Pope Clement VII used it to escape the violent fury of Charles V's Landsknechts.

The historical prisons
Down there, under Alexander VI's courtyard, is a series of rooms hollowed out from the thickness of the cylindrical walls of Hadrian's original mausoleum. Their original purpose was to provide storage for food, corn, oil and water, which was channelled into the prisons from the river Tiber and passed through three cisterns to filter it. As you descend towards these dungeons, passing through the Parlatoio (where prisoners might be allowed to meet visitors), you find yourself in a corridor with a very low ceiling, leading to the storage chambers. These cells were used to hold prisoners from the Renaissance to the nineteenth century, including Pope Paul III (Alexander Farnese), the Italian humanist Julius Pomponius Laetus, the goldsmith, sculptor and painter Benvenuto Cellini, the religious reformer Giordano Bruno, the young noblewoman Beatrice Cenci and the notorious occultist Count Cagliostro.
The tale of Beatrice Cenci, a young member of the Roman aristocracy who lived and died at the end of the sixteenth century, is one of the more tragic human stories of imprisonment in the Castle's dungeons. To escape her father's incestuous attentions, Beatrice had him murdered. Although her actions were justified (by the morals of her day), she was decapitated in the square in front of the Ponte Sant'Angelo, or Aelian Bridge, watched by a huge crowd that sympathised with her cruel destiny.

Clement VII's bathroom, a real jewel of architecture and decoration dating back to the first half of the sixteenth century and named after the Pope who commissioned its completion, was the private bathroom used by the Popes, including a small bathroom proper, a room downstairs used for heating water and an upstairs room used for disrobing. The bathroom is actually a very small room indeed (only 260 x 150 cm.), entirely decorated by Giovanni da Udine, who probably worked to designs by Giulio Romano, using stucco and frescoes depicting grotesques with putti, dolphins, swans and plants, worked around scenes from mythology and the thrones of the Olympian gods, who also left their robes and divine attributes, so as to accompany the Pope - at least in an imaginary world - in the ritual of bathing.
The Castle's bathroom is of singular importance because it is one of the very few Renaissance bathrooms to have survived to this day. The name bathroom comes from such rooms' conceptual derivation from ancient Roman baths, whose habitués used to take the therapeutic benefits of steam.