Tourists going about their day sightseeing with the Arch of Constantine and the famous Colosseum landmark in the background, Rome, Italy

arch of constantine colosseum landmark people tourists sightseeing rome italy architecture design structure unesco world heritage site iconic famous walking busy visitors constantine arch triumphal via di s gregorio pave colosseo building heritage historical history monument attraction ancient beautiful outdoors gloomy arena amphitheater tourism travel amazing spectacle facade exterior establishing europe roman empire