No doubt you have seen these buses in many cities around the world. I had not realised how great they are until I actually used my first one. I have since used this system in many cities. This system also gives you the opportunity to easily plan your stay in the city.
All the major landmarks are included in the trip, so you can hop off at any one and stay as long as you like or as little as you like as there are many of these buses travelling around the city all day and well in to the evening.
The ticket that you purchase is usually for a 24 hour or 48 hour period starting from your first bus ride. You can hop off and on as many times as you like.
Little tip, make sure you also allow time for an evening trip. The days are great but it is amazing how different a city can look at night.
One of the most fun experiences I had was on the one in Rome. We had been sightseeing during the day and decided to have a small trip just before going to dinner. We sat upstairs at the front of the bus, and mama mia, the traffic was unreal and the way the driver handled it all was fantastic. We were so impressed with his driving skills and, we had a super time.
The bus in Florence takes you into the hills to over look the city. Beautiful.
Of course you can also combine this with walking. The time on the bus gives you a chance to rest your legs and re charge.