Even if Rome’s streets did not evolve with London style open-top buses in mind they are now common place and the service is both frequent and modern. There are three companies operating the hop on hop off tours, which are 110 open-top, Archiobus and Christian Rome. All provide a service with an audio guide and are a good way to get orientated, get across town from say the Colosseum to the Vatican or out of the centre to the Appian Way. Due to their size they are not n appropriate option for getting into the charming narrow streets of the historic centre.
Something to keep an eye open for are the joint tourist bus and state owned museum promotions, which save you a few Euro but more importantly allow you privileged access. The 110 open top Caravaggio Card, was very much the least compromising way to avoid the often 4 hour plus queue for this phenomenally successful exhibition.
The River Tiber has never been central to the city as it always made up part of the defences until modern times. Flooding was a common problem until the 1870s when the embankments were built then with hydro-electric damming up wrecks washed up at the foot of the Spanish Steps became a thing of the past.
Today a trip on the water is well worth scheduling in as it is the only way to really appreciate sites like Castel St. Angelo, the bridges and Tiberius island. The Battello su Tevere service offers a range of cruises with commentary. You can even go all the way to Ostia Antica on the water with a glass of wine in hand. For full information visit www.battellidiroma.it
The buses cost 15 Euro for the day. A three-day pass costs 40 Euro. You can buy tickets on board from the reps. For special promotions you need to go company ticket offices located outside Termini Station. Tickets for the cruises start at 1 Euro for a “water bus” service and go up to 60 Euro for an evening cruise with dinner. A standard cruise down the section of the Tiber with the most sites costs 15 Euro.