With your prepaid ticket in hand, make your way to one of the eight stops on the bus route. Choose between a 24-hour or 48-hour ticket when booking, according to your interests, schedule, and budget. You can also choose to add admission tickets to the Sistine Chapel, the Vatican Museums, Palatine Hill, the Roman Forum, and the Colosseum to your hop-on hop-off ticket, which saves time spent waiting in ticketing lines.
Step on board the bus and choose a seat in the covered portion of the bus or the open deck up top. Listen to the audio commentary with historical and cultural information about each sight as you pass. If you stay on board the entire time, the loop takes between 1.5 and 2 hours; otherwise, you can choose to get off at any of the stops and explore further on your own.
See the Colosseum where gory gladiatorial battles once took place, and have your camera ready for Piazza Venezia, home to the Vittorio Emanuele II Monument. Throw a coin into the Trevi Fountain for luck, or stretch your legs on a walk through Vatican City.