Here you can find some travel information about which general route to take for arriving at the Certosa di Pontignano from the main airports next to Siena and Florence train station. Details like timetables then can be found via the conference's website:
http://www.unisi.it/eventi/practical_philosophy/

FLORENCE / FIRENZE AIRPORT TO CERTOSA DI PONTIGNANO
1. At Florence Airport you take the bus "vola in bus", which brings you to the Florence's bus terminal. There is a "vola in bus" every 30 minutes, and the trip takes about 20 minutes. The ticket can be bought on board.
2. From Florence's bus terminal you take the bus to Siena, Piazza Gramsci / Lizza (terminal stop of the bus). There is a bus about every hour, and the trip takes 75 minutes (provided you take the "rapida" and not the "diretta", which needs 20 minutes more). The ticket has to be bought in the ticket office of the bus terminal. The time table can be found on the website of "TRAIN" (there is a respective link on the conference's website).
3. From Siena, Piazza Gramsci, you take a cab to the Certosa di Pontignano. (There is also a bus connection to the Certosa but with few courses only. These connections can be found on the webpage of "TRAIN" if you look for the destination "Ponte a Bozzone"; the bus that drives to Ponte a Bozzone continues to the Certosa di Pontignano.)

PISA AIRPORT TO CERTOSA DI PONTIGNANO
1. From Pisa Airport you take a train to Siena. Pisa Airport has its own train station. But sometimes it is better to first take an urban bus (5 minutes ride) to Pisa's main station and to start the train travel there because from Pisa's main station there are further connections to Siena. There is a train connection from Pisa to Siena about every 2 hours and the trip takes 2.5 to 3 hours. Usually from Pisa you have to take a train that goes to Florence, but you have to change the train before arriving in Florence, namely in Empoli. The connections can be found on the Webpage of "Trenitalia" (www.trenitalia.it).
2. From Siena Train Station you take a cab to the Certosa di Pontignano. (There is also a bus connection to the Certosa but with few courses only. These connections can be found on the webpage of "TRAIN" if you look for the destination "Ponte a Bozzone"; the bus that drives to Ponte a Bozzone continues to the Certosa di Pontignano.)

ROMA FIUMICINO AIRPORT TO CERTOSA DI PONTIGNANO
From Rome you have two main possibilities to continue to the Certosa di Pontignano, or by buy or by train. Both takes about the same time (41 minutes local train plus 2:45 hours bus or 31 minutes local train plus 3:15 train). If you take the train you have to change in Chiusi (or Grosseto), and there is some risk to miss the connecting train there.
1. Main travel by bus:
1.1. From Roma Fiumicino Airport's train station you take a local train that brings you to Roma Tiburtina, i.e. the second largest train station of Rome. There is a train every 15 minutes and the course takes 41 minutes. The time table is available at: www.trenitalia.it.
1.2. Next to the train station Roma Tiburtina there is the travel office of the SENA Bus Company, where you can get the tickets to Siena. The bus stop is next to the travel office. The time table is available at: www.sena.it. Buses depart at 6:30, 8:30, 10:30, 12:30, 14:00, 15:30, 17:00, 18:30, 20:00 and in some days: 21:30. And the course takes about 2:45 hours. You should get off the bus either at Siena train station or at Siena, Piazza Gramsci / Lizza.
1.3. Take a cab to the Certosa di Pontignano. (There is also a bus connection to the Certosa but with few courses only. These connections can be found on the webpage of "TRAIN" if you look for the destination "Ponte a Bozzone"; the bus that drives to Ponte a Bozzone continues to the Certosa di Pontignano.)
2. Main travel by train:
2.1. From Roma Fiumicino Airport's train station you take a local train that brings you to Roma Termini, i.e. the main train station of Rome. There is train every half hour and the course takes 31 minutes.
2.2. Continuation by train: From Roma Termini take a train connection to Siena, for which you have to change in Chiusi (or Grosseto). The time table is available at: www.trenitalia.it.
2.3. Take a cab to the Certosa di Pontignano. (There is also a bus connection to the Certosa but with few courses only. These connections can be found on the webpage of "TRAIN" if you look for the destination "Ponte a Bozzone"; the bus that drives to Ponte a Bozzone continues to the Certosa di Pontignano.)

FLORENCE / FIRENZE TRAIN STATION TO CERTOSA DI PONTIGNANO
1. Florcence's main train station is "Santa Maria Novella" (or S.M.V. for short). Walk (about 100 m) from there to the main bus station (SITA bus station): Santa Maria Novella is a terminus. Having arrived at the end of the rails turn to the right and take the right exit. Cross the street, and, depending on where exactly you have crossed the street, first turn left, walk to the traffic light and turn right there (in the Via Santa Catarina da Siena) or, if you have crossed the street at the main junction, go simply ahead (in the Via Santa Catarina da Siena). After about 30 m on your right is the entrance of the SITA bus station.
2. From Florence's bus terminal you take the bus to Siena, Piazza Gramsci / Lizza (terminal stop of the bus). There is a bus about every hour, and the trip takes 75 minutes (provided you take the "rapida" and not the "diretta", which needs 20 minutes more). The ticket has to be bought in the ticket office of the bus terminal. The time table can be found on the website of "TRAIN" (there is a respective link on the conference's website).
3. From Siena, Piazza Gramsci, you take a cab to the Certosa di Pontignano. (There is also a bus connection to the Certosa but with few courses only. These connections can be found on the webpage of "TRAIN" if you look for the destination "Ponte a Bozzone"; the bus that drives to Ponte a Bozzone continues to the Certosa di Pontignano.)