We loved our night at Palazzo di Valli. The walk to Siena took about 20 minutes. It is all "uphill" going in, and "downhill" on the way home. The innkeepers were helpful both before and during our stay with everything from public transit instructions to restaurant recommendations. Breakfast was simple and lovely.
Ask for a room with a view. One side of the property looks out over the Tuscan countryside. Waking up with that view was a highlight of our time in Siena.
The room was quiet, clean, and comfortable. Highly recommended!!!