Message left by guest that visited from the USA in June 2017: Being car-less has been totally easy. Buses a bit unpredictable but the trains are perfect. My one tip for any future guests on-foot is: to get to the castles, talk to any cabbie. They seem very excited about shuttling folks around for an hourly rate, and they are willing to negotiate. We're going on a 5 hour trip today to both castles, the bridge, and LlanfairPG. Driver offered £35/hour and we settled on a flat rate of £120. Not cheap, but better than trying to navigate multiple bus lines. Just sharing in case it's of use in the future. :-)