Hiya Dan, I live in North Hampshire, we have a rolling Countryside and a Mountain of our own.. A lump called Beacon Hill, it is a mound of Chalk 261m above sea level and takes a Calf muscle busting 20mins to claim the summit...
I have been to the Brecons 3 times but only to walk once, the other two were for work.. I must make more effort to return, it's only a two hr drive after all... You lucky you is..