castel sant`angelo mausoleum of hadrian - castle of the holy angel a towering cylindrical building in parco adriano, rome

adriano aelian aelius ancient angel angelo angels arches architecture attraction basilica borgo bridge building castel castle city cylindrical emperor engineering europe european fortress hadrian historic history holy italian italy landmark marble mausoleum museum parco pedestrian peter petri pons ponte rioni river roman rome saint sancti sant sculptures the tiber tourism tourist tower travel travertine vatican