In reply to Gorilla:
If you want a town close to Peny fan- go for Brecon. A nice village is Crickhowell - good pubs and restaurants. approx 20 mins from brecon.
Other low level walking is very nice in the valleys and waterfall country south of the Beacons near Pontneddfechan
When you arrive - they are called the Beacons rather than the Brecons
cheers - bill