Castel Sant' Angelo
Castel Sant' Angelo
(kästĕl` säntän`jālō),Hadrian's Mausoleum,
orHadrian's Mole,
massive round construction on the right bank of the Tiber in Rome. Originally built (A.D. 135–39) by Emperor Hadrian as a mausoleummausoleum, a sepulchral structure or tomb, especially one of some size and architectural pretension, so called from the sepulcher of that name at Halicarnassus, Asia Minor, erected (c.352 B.C.) in memory of Mausolus of Caria.
..... Click the link for more information. for himself and his successors, it was later decorated and fortified as a place of refuge for the popes and was connected to the Vatican by a secret passage. It was used as a fortress and prison until 1870 and is now a museum.