Within old Siena, the B&B Piazza Duomo is located approximately five minutes by foot from the Campo and the Duomo, very convenient for exploring the medieval streets of the city.
Our room was much larger than expected, clean and well-furnished, and considering the reasonable price of the B&B more than to be expected.
The owner Emanuele was very helpful and gave us tips for two restaurants, both of which were within a short walking distance and offered authentic Sienese cuisine.
The B&B consisted of a few rooms and a kitchen and breakfast area where guests could prepare their own meals. Internet access was availible.
Regarding the parking situation: if you follow the directions to the letter, you will be able to find the hotel, stop in front of it for two minutes to unload and then find the free parking spots mentioned - if they are not already taken. Driving in this medieval city is not simple, however, and signs are not very easy to find. Patience and a bit of humor are a must.
This B&B was quite good, especially for the price, and I would not hesitate to stay there again.