I went to Wales once. Two weeks.
Climbed these mountains:
Glyder Fawr. (VERY difficult)
Mole 'y Guest - That's if you can call it a mountain. It's more of a large rocky hill
Cader Idris - Nice easy climb, this one. Just don't get sun or wind burn. Ouch!)
Brecon Beacons - That's a hard one, but not as hard as Glyder Fawr
Then I did a 16 mile treck across the Black Mountains. That was a nice walk, but quite a bit painful.
Anyway, I had fun there as you can see, so I hope you have fun too.
- DH