Buses to Krakow from Europe

Hello.
This is a little special question:

My friend is abroad (in Europe) and on her way back to Krakow.
She wants me to guess where she has been.

She is going by bus tomorrow morning (Sunday) at 07.40am and will be back in Krakow ( still by bus) about 05.30am on Monday, after about 22 hours bus ride.

My task is to guess where she has been.
Any suggestions??

Thank you :)

P.

well the trip to Krakow from London is as follows (operated by a polish company via eurolines)

London
Dover
Calais
Belgium
Netherlands
Germany ... come to the Frankfurt (oder) section
Poland - Zielona Gora .. Legnica ... Wroclaw ... Opole ... Katowice ... Gliwice ... Krakow

or maybe she is using the Sindbad coach company check here lists the Europe countries travel from and destinations there travel through

sindbad.pl/index.php?go=1878

Thank you...
Seems reasonable.

I will find out when she comes.. she just wanted to "test" my geograhpy knowledges..

P :)