Depends on where you are staying. If you are in a big "tour hotel" out in the suburbs then no, they are not walkable from your hotel. You'll need to take the Metro (subway) or a cab to get into the heart of Rome. However, Piazza Navona, the Trevi Fountain, the Pantheon, Campo Fiore, etc., are all within a mile or so of everything else named, and are within easy walking distance of lots and lots of hotels in the heart of Rome. If you download Rick Steves' free "Rick Steves Audio Europe" app, there are a number of FREE audio tours that you can download and then use once you are there. His "Heart of Rome" audio tour covers these sites. It also has a map attached to the tour, on the app, that shows you where to walk (and where to get gelato along the way!). You could also pick up a copy of his "Rome" guide (the book) and read about the neighborhoods and look at the possible walking tours of those neighborhoods. That book gives lots of recommended places to eat, in specific neighborhoods.