No special access issues
Access the Clegir Road from Llanberis, go up Goodman Street (opposite Pete's Eats) and keep going out of the village and up the hill as the road narrows. Continue over the first cattle grid as the roads flattens off and continue until a viewpoint is reached with a layby on the right (just before another cattle grid). Alternatively, approach from the Glyn Twyrog pub in Llanrug.
From the layby, take the path down the hill, trending leftwards to find a bay. This is the Mur Pen Clegir boulder.