This cache can be done as a drive by from the Mold Bypass or if you are walking the footpath from New Brighton to Mynydd Isa which intersects the road halfway up the Wylfa Hill stretch. There is a layby ideally placed for a quick drive by - though I would advise using the roundabout a few hundred yards down the hill rather than a risky right turn manouvre!
The Mold bypass was built in the mid 1990s to relieve pressure from increasing traffic through this busy market town, and this stretch joins the original road at New Brighton with the Buckley and Wrexham connections near the banks of the River Alyn. The word 'Wylfa' in Welsh means a lookout or an observation post, and this hill would have been an excellent vantage point to see what was happening in the valley below.
*As this is near a busy road with high speed traffic please keep a close eye on kids, dogs and Geocachers!*
**CONGRATULATIONS TO TEAMC&P - FTF!** UPDATE (JUNE 2020): Due to a number of people having more trouble than I'd expected, I have amended the hint. Hopefully this will make it more straightforward, but we'll see!