Pontprennau

Method 1

From the a48 turn off at Pentwyn taking teh 2nd exit (Pentwyn Road) keeping johnsons 
supermarket on your right. Take the right fork at the first mini roundabout into Croedescarn Road (at Bupa/Paramount Jaguar) 
Take the left fork at the next mini roundabout into Heol Glandulais, then straight over at the next mini roundabout, staying on Heol Glandulais. At the next roundabout turn right, you should see the pitches on your left. A short way up is the mini roundabout from which you can access the community centre where you can park. 

Method 2

From the a48/M4 turn off as if you were going to Asda's at Pontprennau. Instead of turning right into the retail park go straight across that mini roundabout into Heol Pontprennau. Turn left at the T junction, and then 1st right to stay on Heol Pontprennau. Stay on this road until you reach the Community Centre (off a mini roundabout!), but be aware that this road does turn left through 90degrees, with a junction off it at the point of the bend.