I cannot really say that I have spent a lot of time in Wales, but one place I have been to is Snowdonia -- my mother wanted to climb Cader Idris, but realized soon upon arrival that it is not so easy as just an afternoon hike!
Roughly translated as 'meadow of groves', it is a small stone village with narrow alley-like streets similar to many others in Britain, but it is a excellent base for exploring Snowdonia National Park and doing the Mawddach (River) Trail. Historically, it was settled after it was established as a serf village (maerdref) around the early 12th century. It has variably had influence from the wool industry, Quakerism, a minor gold rush, and now tourism.
What's there to see? A pleasant church (built in 1716), standing stones on the village green, the 12th century Cymer Abbey, Camlan field (supposedly site of the last battle of King Arthur), pretty arched bridges, as well as historical narrow-gauge heritage railways. Lovely hiking nearby!