Fast trains (Trenitalia or Italo) stop at Napoli Central Station (Stazione Centrale di Napoli). From there, essentially three options are available:
Take the bus 151 and get off at Piazzale Tecchio, which is an important bus station just in front of Napoli Campi Flegrei train and metropolitan train station. At Piazzale Tecchio, it is possible to switch bus (see below). It is also possible to proceed on foot. The path from there to Monte Sant'Angelo passing on the left hand side of the Diego Armando Maradona Stadium (which you will see immediatly in front of you) is in fact almost perfectly straigth (but it is uphill!). It takes around 45 minutes on foot and around 5/10 minutes by bus.
Take Metro Linea 2 (direction Pozzuoli) and get off at Napoli Campi Flegrei (piazzale Tecchio). Then, apply point 1.
Take a cab. Ask for tariffa a tassametro, with destination Monte Sant'Angelo - Fuorigrotta (ask the driver to leave you inside the campus). The approximate charge will presumably be around 18-20 euros.
BY BUS (ANM Napoli)
Connections Napoli Centrale, piazza Garibaldi - Napoli Campi Flegrei, piazzale Tecchio: bus 151, Metro Linea 2 (direction Pozzuoli), Napoli Campi Flegrei stop.
Connections Piazzale Tecchio - Monte Sant'Angelo: Bus 180, R6 and 615.
There is a bus line from the airport (Aeroporto di Capodichino - Napoli) to the railway station (Napoli Stazione Centrale, piazza Garibaldi) called Alibus.
To get directly to the Department, take a cab from the airport. Ask for tariffa predeterminata, with destination Dipartimento di Matematica inside the campus of Monte Sant'Angelo - Fuorigrotta (ask the driver to leave you inside the campus). The approximate charge will presumably be around 23 euros.
BY CAR
Arriving to Naples from the highway, take the Tangenziale di Napoli to the exit Fuorigrotta. The junction on the right bring you in via Cintia. When you reach the traffic light, you can see the main entrance of the campus on your left.