We will be in Sienna just for an afternoon. We will be driving to the city. As i understand, if you park in the regular car parks, it is uphill to the Campo, and old section. So since my daughter is in a wheelchair, that is pretty much out. If we park at the train section, and are there buses that get you pretty close to the Campo? I understand the city is VERY hilly, so even if we just stay around the area of the Campo, I really would like to see a little bit of Siena if possible. Any suggestion?