Castel Saint’Angelo, the former Mausoleum of Hadrian, is located on the right bank of the TiberRiver, next to the Ponte Sant’Angelo, in Rome, Italy.The fortress was completed between 135 and 139 AD by the Roman Emperor Hadrian as a tomb for him and his family.His ashes were placed here after his death in 138, as were the ashes of all subsequent emperors until Caracalla in 217.In 410 the Visigoths sacked Rome, led by King Alaric.The castle, by then a fortress, was sacked as well and the urns containing the ashes of Hadrian and his fellow emperors were scattered to the wind by the looters.In 590 Pope Gregory the Great had a vision of the Archangel Michael sheathing his sword over the castle which signified the end of the plague in Rome.From this incident the castle gained its new name Castel Saint’Angelo, which means Castle of the Holy Angel.The popes took advantage of the castle’s close proximity to the Vatican and constructed a corridor from the castle to Saint Peter’s Basilica, known as the Passetto di Borgo, which allowed easy escape in times of trouble to the more fortified Saint’Angelo.Paul III had an apartment worthy of a pope later constructed within the fortress in case the need for a long term residence would ever be required.In this way the pope would have a lavish room to call his own while he waited out whatever siege might be occurring at the time.A marble sculpture of St. Michael by Raffaello da Montelupo was placed atop the fortress in 1536.It was subsequently replaced with a bronze statue by Peter Anton von Verschaffelt in 1753, which still sits atop the castle.In later years the fortress was converted into a prison, finally being decommissioned in 1901.It now serves as a museum.