Bus number 64 is the one we used to go to Vatican. We took it on Termini station and has few stops before arrive. Careful because pickpockets used to go on this bus.
El autobus num 64 es el que va al Vaticano desde Termini, nosotras lo cogimos alli. Hay que gastar cuidado porque en este autobus suelen ir bastantes carteristas.
From Rome Termini station, take bus 64 or 40 (Express) to the Vatican. A one-way ticket will cost you EUR0.77. Alternatively, you can take the metro to San Pietro station. From the city centre, just cross the river and walk up the Via della Conziliazone.
Here's a map to give an overview of how small the Vatican actually is. Most of its visitors will only see St Peter's Basilica and the museums anyway.
I stayed at a hotel near the train station and took the bus to the Vatican.
I mostly walked the city.
The buses or by foot!
You can see me on the Vatican Museum staircase.