But lately, the city has fallen victim to a different kind of threat -- that of indifference and questionable city governments that have left its grandeur dirty and decaying.
The mosaics and frescoes are still safe within the fortified walls of the great palaces and museums, but it is far more likely that any recent visitor will instead remember the graffiti and the garbage spilling over onto the cobblestone streets. Buses don't run on time and frequent labor union disputes lead to strikes that shut down public transportation altogether.
So dire is the situation that a group of city activists who work under the banner "Roma Fa Schifo" (Rome is Disgusting) chronicle the degradation on a website and Twitter feed with more than 150,000 followers.
This city is also lately filled with migrants who suffer from a recent backlash that is pushing right-wing anti-immigration parties to the forefront ahead of Sunday's elections
Rome has no official center for migrants waiting for word on their political asylum requests, so many camp out near the main train station or settle in any number of shanty towns that have sprung up along the banks of the city's Tiber River.
In January, CNN visited an abandoned multi-story university building known to its inhabitants as the Selam Palace, where nearly 1,000 Ethiopian, Eritrean and Somali refugees who have been granted legal refugee status squat illegally because the city can't find legitimate housing. There are more than 50 other abandoned office buildings just like it throughout the city.