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. 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, was erected between 135 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.