Bus – TEC (transport en commun en Wallonie)
1 bus ride 1.90 euro (you can buy this on board)
1 day ticket 4.00 euro
3 days ticket 8.00 euro
8-ride card 8.80 euro (6.40 reduced)
more info here http://www.infotec.be/
Trains – SNCB (société nationale des chemins de fer belges)
Rail pass: 10 travels everywhere on the Belgian rail (border excluded) for 76 euro
Go pass: same as rail pass but for <26 people for 50 euro