The three-hour tour includes: The Roman Forum and its buildings, the Sacred Route, the Palatine Hill (including the Emperor’s Palace) and the Colosseum.
The four-hour tour includes: The Roman Forum and its buildings, the Sacred Route, the Palatine Hill (including the Emperor’s Palace) and the Colosseum plus the Capitoline Hill and via dei Fori Imperiali (the Fora of Trajan, Augustus and Caesar).