There are a couple of ways to get to Banja Luka:
With a plane
There are direct flights from Ljubljana (SLO) and Zürich (CH) to Banja Luka. You can check the timetable here.
With a bus
There is a very good bus connection between Banja Luka and Zagreb (CRO), with eight departures a day. Check the Zagreb Bus Station website (http://www.akz.hr/EN/voznired.aspx) to see the timetable. The trip can take from 2.5 to 4 hours, depending on the route the bus is traveling.
There are as much as 18 daily buses from Belgrade to Banja Luka. The trip can take between 5 and 8 hours, depending on the route the bus is traveling. You can check the current timetable on the Belgrade Bus Station website (http://www.bas.rs/basweb_eng/redvoznje.asp).
There are three daily buses from Sarajevo to Banja Luka, departing at 9:15, 14:30 and 15:30. The trip takes about 5 hours.
With a train
There are direct train connections to Banja Luka from Belgrade, Zagreb and Sarajevo. You can check the timetable here: http://www.hznet.hr/timetable
Once you are here, you can take a look at our city map to figure out how to get to the swimming pool.