An important travel tip for Rome: Buy a ticket for the The Big Bus Tour

Big Bus Tours
Big Bus Tours is the largest operator of open-top sightseeing bus tours in the whole wide world. Inspiring the spirit of adventure in over 25 cities, across four continents. Beginning with a fleet of three, today hundreds of buses and guides are helping over four million tourists explore each year.
All buses are equipped with wheelchair ramps and there is of course room downstairs. However, the only way to reach the upper deck is by going up the steps
The aim of this service is simple: to make hop on, hop off sightseeing the number one thing to do on your city break, offer a day or two (or three) of memorable, cultured and even educational fun and to help you tick off the best bits their world-famous cities have to offer, and then some.
Big Bus Tours is the largest operator of open-top sightseeing bus tours in the whole wide world.
All buses are equipped with wheelchair ramps and there is of course room downstairs.
While in Rome, Italy, the Big Bus Tours represented our first activity, Seated on the top deck it represented the perfect introduction to the city and the best photo opportunities of iconic landmarks. This daytime sightseeing tour showcased the Eternal City in all of its glory: the Colosseum, Circus Maximus, Piazza Venezia, Piazza Navona Fountain,Vatican City, and more, with stops located nearby so we could hop off the bus to explore them at our own pace. During the tour, we were able to tune in to pre-recorded commentary, which is available in a variety of languages
When you book the tour you will need to select the date you’d like to hop on the bus. If you’re touring with them for more than one day, your ticket must be used across consecutive days, and the date you select at time of booking should be the first day of your tour. Some tours also require you to select a time of travel, to secure your seat. If your ticket has extra inclusions, you may also need to book dates and times for these inclusions after your purchase is complete via their Booking Portal.
Services operate daily from 9 am to 6 pm so see the Service Information page on their website for tour schedule information and notices. Alternatively, you can check times with a Big Bus Tours team member, Buses pull up at each stop every 20 minutes
Educational and informative pre-recorded commentary are available on board all buses. Tune in via complimentary headphones to learn secrets and stories about the rich history of Rome, its famous inhabitants, dazzling architecture and vibrant culture. Commentary is available in the following languages: English, Italian, Spanish, French, German, Brazilian, Portuguese and Mandarin Your complimentary headphones are distributed when you board the bus. They are brand new and you are welcome to keep them!
Info: https://www.bigbustours.com/en/rome/rome-routes-and-tour-maps