I took our caravan for daughter to Caravan and camping club approved site last junction off A55 before Holyhead, then right off the A5 through a lovely little village and it was on right hand side, hard standings near the house, but daughter wanted no children site so we used the field, it was a bit spongy but no problem with the Kia Sorento had to put one wheel on bit of paving to level but site it seems was good, daughters only complaint was bird song woke her up.
I missed the site completely at first, wife's sat nav took me around Holyhead, Then the sign was slightly over grown so missed stopping in time and had to reverse into a drive and turn around, Also on leaving found it tight on gate way, kicked wife out to check OK, but it was, no need to reverse and try again, think my caravan around 16 foot would not want to take a 20 foot van on the site.
Sorry don't have address off hand, very peaceful, except for birds. and good views out of the window, depends what you want of course, clearly if you have children it's a non starter.
When we went wrong and were on Holyhead I said to wife with these narrow roads there will not be any caravan sites up here, you must have made a mistake, wrong around next corner there was a caravan site, towing with Sorento being high up not really a problem, but would not have liked that road if towing with Jag XE so it seems much depends on what you are towing and what you are towing with, I think some thing like 85 sites on Anglesey one we used just 4 hard standings about 10 spaces in all. There was electric hook up, about first time used whole 25 meters to reach the socket keeping out of way of cars.