How to get to Siena
The train takes about an hour and a half from Florence to Siena and runs frequently every day. If you're coming from Pisa you may have to change trains at Empoli.The train from Roma is a bit more awkward and not as frequent: you have to change trains in Chiusi.
The Siena train station is about 1.5 kms from the historic center of the city. The walk is pretty much all uphill.
You can order your tickets online, pay by credit card and pick them up at electronic ticket machines in the larger cities such as Rome, Milan and Florence.
For more information visit the Italian Railway web site -- in English and user-friendly.
One of the fastest and easiest ways to travel around Tuscany, and particularly between Rome and Siena or Florence and Siena is by bus. The SITA bus station is just around the corner from the train station in Florence. SITA buses to and from Siena take just under an hour, run frequently, and lets you off in Siena's historic city center. Make sure you take the"rapide (express) and not the ordinarie (which stops in Poggibonsi and Colle Val d'Elsa.)
Check their schedule online. The site is only in Italian - click on last link for Orari linea Firenze-Siena. Clicking that will open a .PDF of the schedule that you can download to your desktop.
There is also bus service from Pisa airport to Siena via Siena's local Tra-In bus service. You can access their schedule online. You can get around Siena and its neighboring communities easily by the local Tra-In system as well. Learn about local Siena bus services online.
If you're going from Rome to Siena you'll want to visit the Sena (not it is NOT SIena) bus company's web site.
--> If you're planning to get to Siena as soon as you arrive by airplace, know that it is easier to get from Florence to Siena than from Pisa using public transportation.
Getting to Siena by car takes about two hours from Rome or forty-five minutes from Florence. It's what to do with your car once you've gotten there that presents the greatest challenge. Remember that auto traffic is strictly limited inside the city walls so unless you have special authorization from your hotel be prepared to park outside.
Parking near the city walls has become quite challenging for locals and tourists alike. Most parking is metered. Here is a useful article on parking in Siena with a list of the parking lots around the walls and even free parking areas where you can leave your car.
There is a free parking lot next to the fortezza and a pay lot on the other side of the fortezza next to the La Lizza Park; there is also a pay lot nearby at the nearby soccer stadium. Note however that these pay lots are unavailable on market Wednesdays and soccer Sundays. Parking along the street next to the fortezza is free, although parking down some of the side streets is metered. Check first.
There is a pay parking lot at Porta Tufi (signposted "Il Campo Parking"), a 15-20 minute walk to the Piazza del Campo. There's another pay lot at Porta San Marco (southeastern part of the city), as well as metered parking on the street leading into Porta Romana (southwestern part of the city) and a parking garage by Porta Ovile (also metered).
For more information on parking in Siena, you can visit the Siena parking web site (in Italian only).
If you're staying overnight in the city, check with your hotel or landlord to see what your parking options may be.