'Allo there!

I'm afraid I can't offer any advice on SW Wales, but I do use the public transport to go look at rocks and stuff. I don't drive either, not without big red letter 'L's anyway.

Up here in the north east, I've found that a combination of train and cycle is pretty good for getting to see stuff. It even gets you to places you might not bother with in a car, as you don't have to worry about parking. It might be an idea to have a gander at the tma map browser and work out which sites are within easy cycling of a train station (assuming you has a bicycle of course, if not, ignore me, I'm waffling). By bike, you get to see old rocks, have a bit of exercise, and you still get time to read :)