For those who come by plane, 7 days a week, there are trains from the airport to the Main Station. The journey takes around 16 minutes. The ticket costs 17 PLN (~4€). The new train station is located near the passenger terminal. The schedule you can find here.
One can also take a taxi which should cost around 90 PLN (~20€). If you take a taxi ask for the price before you enter it. We advice to use only the registered taxi companies and to ask for a receipt.

More information can be found on Kraków Airport Page.

For those who come by train we suggest to take the bus number 179 and leave at the stop called AGH / UR 02 (stop number 5) which is the nearest stop from the Auditorium Maximum.
The taxi fare should not exceed 50 PLN (~10€).

The city transport system in Kraków includes buses and trams.
There are two zones of transportation. Zone I "City Cracow" covers almost whole Kraków excluding its suburbs e.g. the airport. All tram lines. Zone II covers suburbs of Kraków (e.g. the airport). All buses with numbers starting with 2 go to the second zone but when one uses such a bus within the zone I, one does not need to cancel the ticket for zone II. All night bus and trams lines within the zone I start with 6 and within the zone II start with 9.
Ticket tariff, remember to validate your ticket after boarding the vehicle (only once in case of the short-term tickets).