Vice versa

The Mausoleum of Hadrian, usually known as the Castel Sant'Angelo (English: Castle of the Holy Angel), is a towering cylindrical building in Parco Adriano, Rome, Italy. It was initially commissioned by the Roman Emperor Hadrian as a mausoleum for himself and his family. The building was later used by the popes as a fortress and castle, and is now a museum.

The tomb of the Roman emperor Hadrian, also called Hadrian's mole, was erected on the right bank of the Tiber, between 130 AD and 139 AD. Originally the mausoleum was a decorated cylinder, with a garden top and golden quadriga. Hadrian's ashes were placed here a year after his death in Baiae in 138 AD, together with those of his wife Sabina, and his first adopted son, Lucius Aelius, who also died in 138 AD. Following this, the remains of succeeding emperors were also placed here, the last recorded deposition being Caracalla in 217 AD. The urns containing these ashes were probably placed in what is now known as the Treasury room deep within the building. Hadrian also built the Pons Aelius facing straight onto the mausoleum – it still provides a scenic approach from the center of Rome and the right bank of the Tiber, and is renowned for the Baroque additions of statues of angels holding aloft elements of the Passion of Christ.

Much of the tomb contents and decorations have been lost since the building's conversion to a military fortress in 401 and its subsequent inclusion in the Aurelian Walls by Flavius Augustus Honorius. The urns and ashes were scattered by Visigoth looters during Alaric's sacking of Rome in 410, and the original decorative bronze and stone statuary were thrown down upon the attacking Goths when they besieged Rome in 537, as recounted by Procopius. An unusual survivor, however, is the capstone of a funerary urn (probably that of Hadrian), which made its way to Saint Peter's Basilica and was incorporated into a massive Renaissance baptistery. The use of spolia from the tomb in the post-Roman period was noted in the 16th century - Giorgio Vasari writes:

...in order to build churches for the use of the Christians, not only were the most honoured temples of the idols [pagan Roman gods] destroyed, but in order to ennoble and decorate Saint Peter's with more ornaments than it then possessed, they took away the stone columns from the tomb of Hadrian, now the castle of Sant'Angelo, as well as many other things which we now see in ruins.

Legend holds that the Archangel Michael appeared atop the mausoleum, sheathing his sword as a sign of the end of the plague of 590, thus lending the castle its present name. A less charitable yet more apt elaboration of the legend, given the militant disposition of this archangel, was heard by the 15th century traveler, who saw an angel statue on the castle roof. He recounts that during a prolonged season of the plague, Pope Gregory I heard that the populace, even Christians, had begun revering a pagan idol at the church of Santa Agata in Suburra. A vision urged the Pope to lead a procession to the church. Upon arriving, the idol miraculously fell apart with a clap of thunder. Returning to St Peter's by the Aelian Bridge, the Pope had another vision of an angel atop the castle, wiping the blood from his sword on his mantle, and then sheathing it. While the Pope interpreted this as a sign that God was appeased, this did not detract Gregory from destroying more sites of pagan worship in Rome.

The popes converted the structure into a castle, beginning in the 14th century; Pope Nicholas III connected the castle to St. Peter's Basilica by a covered fortified corridor called the Passetto di Borgo. The fortress was the refuge of Pope Clement VII from the siege of Charles V's Landsknechte during the Sack of Rome (1527), in which Benvenuto Cellini describes strolling the ramparts and shooting enemy soldiers.
Leo X built a chapel with a Madonna by Raffaello da Montelupo. In 1536 Montelupo also created a marble statue of Saint Michael holding his sword after the 590 plague (as described above) to surmount the Castel.^[4] Later Paul III built a rich apartment, to ensure that in any future siege the Pope had an appropriate place to stay.
Montelupo's statue was replaced by a bronze statue of the same subject, executed by the Flemish sculptor Peter Anton von Verschaffelt, in 1753. Verschaffelt's is still in place, though Montelupo's can be seen in an open court in the interior of the Castle.
The Papal state also used Sant'Angelo as a prison; Giordano Bruno, for example, was imprisoned there for six years. another prisoner was the goldsmith Benvenuto Cellini. Executions were made in the small interior square. As a prison, it was also the setting for the third act of Giacomo Puccini's Tosca from whose ramparts the eponymous heroine of the opera leaps to her death
The Castel Sant'Angelo was featured in Dan Brown's 2000 novel Angels & Demons. The location was the secret lair for the Hassassin and contained the last existing church of the Illuminati. The Passetto di Borgo was described as a secret passageway between the Vatican and the Castel. It subsequently appeared in the 2009 film based on the novel Angels & Demons. The Castel has also appeared in the film Roman Holiday.
The Castel is one of the settings of Endymion and The Rise of Endymion, books in the Hyperion Cantos by author Dan Simmons. However, it is set on the fictional planet Pacem. It serves as a prison and site of the torture of several protagonists in the novels.
The Castel is featured prominently in Puccini's opera Tosca. The Castel serves as the prison and location of execution of Mario Cavaradossi. Floria Tosca also throws herself from the rooftop after discovering Cavaradossi's death to escape capture by Scarpia's henchmen.
In 1980, two American rock bands performed concerts outside the Castel. Kiss performed in August and The Ramones performed in September.
The Castel has appeared twice in the Assassin's Creed game series. It first appeared in Assassin's Creed II, and was featured more prominently in the following Assassin's Creed: Brotherhood. It is depicted as the official residence of Pope Alexander VI and his children Cesare and Lucrezia Borgia.
The design of the McKinley National Memorial in Canton, Ohio, the final resting place of US President William McKinley and his family, was based on the Castel according to its architect, Harold Van Buren Magonigle.

(Source Wikipedia)