Originally Posted by
Giggleswick
Just don't be disappointed if you don't hear Welsh spoken in Cardiff. You may already know this, but a very low proportion of the local population there speaks Welsh.
You'll hear (recorded) Welsh at Cardiff railway station.
You may be able to hear Welsh if you take the train up the valleys past Pontypridd, though it will probably be from children going to Welsh-speaking schools rather than older people. The cwms (cirque in American) are worth having a look at, but it's probably better with a car and not on a short day trip.