I have seen reviews of the Hop-on Hop-off bus. They are very crowded and traffic is terrible in Rome. I decided to get a hotel, Albergo Santa Chiara, near the Pantheon so I can walk almost everywhere. I booked a golf cart tour to take me to Appian Way and Catacombs since it is too far to walk. I will take a taxi to the Vatican for an early morning tour. I can walk to Trevi fountain, Colosseum and ancient areas like Roman Forum, several piazzas, and some interesting churches.