The heart of Rome is its attraction-dense historic center, where you’ll find A-list sights from the Trevi Fountain and the Pantheon to Piazza Navona and Campo de’ Fiori. Toss out the map and guidebook and stroll through the Centro Storico with a guide who can bring these emblematic monuments and squares to life.

For the greatest look at the splendor of ancient Rome, antiquity's best-preserved interior is a must. Built two millennia ago, this domed temple — located in the very heart of Rome — served as the model for Michelangelo's dome of St. Peter's and many others. Engineers still admire how the Romans built such a mathematically precise structure without computers, fossil fuel-run machinery, or electricity. (Having unlimited slave power didn't hurt.) Learn more with my free Pantheon audio tour.