No special access issues
Take junction 17 off the A55 and head towards Conwy. Take the second turning on the right (almost straight away) and head down a dead-end road to an industrial estate. Park sensibly at the end of the road.
Near the layby on the left is a small style. Cross the style and follow the obvious path to the right. Continue to follow the path, trending slightly leftwards up the hill at minor junctions, until you walk under a stone arch. Shortly afterwards, the path will split. Take the left fork, going steeply uphill, going under a second arch, whereby the boulder becomes obvious in front of you.
If a large and incredibly obvious quarry appears on your left, you have missed the last left turn. The boulder sits atop the quarry