Dublin to Wales

yes it is

of course.

I just call it by its usual name of Llanfair PG.

Can't resist mentioning I once had a business associated whose given name was "Linfair." Her mother loved the hymn Llanfair (best known in USA as "Christ the Lord is Risen Today"), so she named her daughter after it. https://hymnary.org/tune/llanfair_williams

My husband and I are planning visiting Dublin then Wales in May, 2020. There are ferries from Dublin to Holyhead, Wales. The trip is just under 4 hours. See: Irish Ferries and Stena Line Ferries.

Hi, Gary! We also are planning a comparable trip and decided to take the ferries in the daytime for the experience of seeing the land approach, the sights of the harbor, etc. We could have booked a night time ferry and just slept through the trip until time to unload; but after another road trip where the ferry ride was the most interesting part (through Galveston, TX harbor area) we realized that it was totally worth the time for us to stay awake for the ferry ride opposed to flying over from Ireland to the UK. A Youtube video was also very convincing on this issue: https://www.youtube.com/watch?v=SwOfZhS-e_g "SailRail From London To Dublin Ireland! Ireland Vacation Holiday Under $2000 For 3 Weeks!" If we were UK or Ireland residents and had taken the ferry many times, we might feel differently and want to fly over and possibly shorten the travel time.

Nonstop flights from Dublin to Cardiff don't operate daily, for instance about 3x/week in May. Try www.skyscanner.com and search for a whole-month window to better see the options.