Not a whole lot to add except seconding some of the places mentioned. I was in North Wales a few years ago, stayed at the Youth Hostel in Bettws y Coed and took day trips to Conwy Castle and through Snowdonia Park. The latter is one of the most breathtaking scenic areas I've ever seen -- and that's having seen most of the sights of North America and a good part of Asia. Wonderful place! Enjoy it.

cheers,

david