Aiports
The most convenient airports are Roma Fiumicino, Pisa or Florence.

-From Roma Fiumicino:
A train, leaving every 30 min, takes you to two possible destinations in Rome:

•Stazione Termini (the central railway station). From here take the train (see below) to Chiusi, and then to Siena
•Stazione Tiburtina. From here take the bus (see below) to Siena

You can look for the time of departure at the following web site: http://www.ferroviedellostato.it/

(departure station Fiumicino, arrival either "roma termini" or "roma tiburtina")

-From Pisa:
A train takes you to Siena. You have to change at Empoli.

-From Florence:
By train: you might have to change at Empoli.

By Bus

There is a very convenient bus both from Rome and from Florence

-From Rome:
The bus leaves from Piazzale Tiburtino (opposite the railway station "Stazione Tiburtina").

It takes just under three hours to get to Siena. Exit at the railway station ("Piazzale Rosselli"), where you will be picked up by a shuttle.

The price of the ticket is 20 euro. You have to buy the ticket at the bus station (office “Sena”, located in Piazzale Tiburtino in Rome and inside the railway station in Siena). Alternatively, you can buy the ticket by credit card at this website:

(a 3 euro transaction fee will be applied)

The times of departure are as follows:

From Rome 6:30 8:30 10:30 12:30 14:00 15:30 17:00 18:30 20:00 21.30

From Siena (railway station) 6:18 7:48 9:18 10:48 12:18 14:18 16:18 17:18 18:18 20:18

-From Florence
The bus leaves from a building just outside the railway station "Santa Maria Novella", called "Autostazione SITA" (Via S. Caterina da Siena 17R).

Take the bus called "Siena Rapida" (this has a very limited number of stops).

It takes one hour and a quarter to get to Siena. The last stop is in the town, at a square called "Piazza S. Domenico". From there you have to walk

(4 min) to "Piazza Gramsci" (reference Jolly Hotel) where you will be picked up by a shuttle. See THIS LINK for directions:
.
The price of the Firenze-Siena ticket is 6.50 euro.

Tickets can be purchased at the office located in the "Autostazione SITA" (the same place from where the bus leaves). Alternatively, they can be purchased on board for 8 euro.

The times of departure are as follows:

From Florence
6:45 8:10 9:10 10:10 11:10 12:10 13.10 14:10 15:10 16:10 17:10 17:20 19:10 20:15

From Siena
6:30 6:40 6:50 6:55 8:00 8:10 9:10 10:10 11:10 12:10 13.10 13:30 14:10 15:10 16:10 17:10 17:40 18:20 19:10 20:10

-From Pisa
The bus leaves from Pisa airport and arrives in Siena in 110 min. It stops both at the railway station and in the city center (square "Piazza Gramsci), where you will be picked up by a shuttle. The price of the ticket is 14.00 euro. The ticket can be purchased on line at the following web site: http://www.trainspa.it/sienapisa.html, and has to be picket up at least 15 min before departure.
The times of departure are as follows:

From Pisa airport:
11:00 17:30
From Siena
7:10 13:20

By car

-From Rome
Take the highway (autostrada A1) in the direction of Florence. Leave the highway at the exit "Valdichiana", and enter the road in the direction of Siena. When you get to Siena enter the "tangenziale ovest" and exit at "Siena Nord". On request I can fax a map with indications about how to get to the Certosa.
-From Florence
Take from the airport the highway in the direction of Rome, then leave at the exit "Firenze Certosa" and take the direction of Siena. Exit at "Siena Nord" (see above)
-From Pisa
The easiest way is to get to Florence (it should be signposted at the airport) and from there follow the indications reported above.