upward view of castel sant'angelo's imposing architecture

archaeology castelsant 039 angelo commanding crenellations cultural defensive edifice emperor eternalcity fortress grandeur heritage iconic majestic mausoleum museum resilience rome romehistory stronghold timeless touristattraction vatican ancient architecture aweinspiring battlements circular fortification fortified historical imposing italian landmark masonry medieval monument papal perspective preservation round sky solid stone structure texture tower upward walls