I love Rome. Yes, parts of it are run-down - ruined, even. But the layers of buildings, one on top of another, some squatting in the ruins of others or re-using materials from them, are what makes the place so magical. The walls between us and the past feel so thin, and you can lose yourself in the place and see why it came to be called the Eternal City.
Over here is the Temple of Vesta, which even the ancient Romans claimed was ancient - supposedly predating the founding of the city itself.
Over there are the ruins of Nero's Domus Aurea, hastily buried under a square mile of earth after his death, partly covered over by the Baths of Trajan and by the Colosseum, then rediscovered by a shepherd boy so we can now visit parts of it. Only in Rome could the fifteenth century feel so recent!
And then there's St Peter's Basilica, of very current relevance to the world's Catholics, but a newcomer by Roman standards, built with bits pillaged from the Colosseum and elsewhere.
It's great! But you have to take your time, take it all in, and think it all through to feel the power of it.
I recommend getting up very early and wandering around it all before the day-tripping tourists arrive.