We will be taking at least one daytrip into Siena, and will have a car.
Is there a place to park outside of the city?
if so, how to get in from there?
Are there car parks in the city?

Thanks for any advice from those who have done this.

Don't fret. It's easier than you might think. There are several large carparks inside the city walls. Depending on which direction you are coming from, just follow the signs. It will be less than a 10 minute walk to the city center. (I'm sure someone here will post more specific directions .)

Hi,
There are many places to park outside of the city. You follow the signs for parking. I read somewhere that the best place to park is near the stadium, therefore we followed the signs to the stadium and found a parking lot. We did not park at the stadium itself, but we found out that is possible and it is a little closer to the town entrance. Then you just follow the signs to the entrance of the town. Remember where you entered the town so when you go to leave you will exit the correct place to find your car. After you do this once, then you realize it is easy. Have a wonderful time.

The two earlier posters are totally correct...it's a heavily touristed town so they know that we don't have a clue where we're going.:-\ Just follow the signs that appear at convenient intervals. We parked at the stadium as well and found it very easy to find.

Thanks both of you.
Exactly what I needed to know.
and it does sound very easy.
as long as I make a note of WHICH car park we use !

Hi Nan. If you arrive early enough in the day, or get lucky, you may be able to park for free on one of the roads leading up to one of the portes, the entrances to central Siena. (If you do this, however, you'll walk further than if you park in one of the large pay parking lots.)

As others have noted, there are numerous large pay parking lots near the various portes. When we couldn't find free parking, the one we used was the large lot near the southern porte (I forget the name of the porte; perhaps someone else will know). It's the closet pay lot to Il Campo (only about a ten minute walk) and I believe the lot is also called "Il Campo."

Hi Capo!
Well, "early enough" is usually not a concept used when talking about teenagers and morning, :lol
But, I will look for the Il Campo or the stadium lot.
Thanks.
Also got Cortona on my daytrip list as you suggested.

We got totally lost trying to find a parking spot within the city walls, and ended up parking in an underground car park, for free at the railway station. It was only a hsort walk to the city center. Not sure if it was supposed to be for free....