Lovely spot. Mostly a flat gravel access road for the reservoir, then a short tussocky stretch up to the boulders themselves, few minutes max. Mostly a single cluster of boulders and very compact. I had a walk on to the Hammerhead but that's a bit more of a flog. Cow's Mouth is a similar flattish walk from the White House pub nearby. You could go onwards to Stony Edge from there, but further and more spread out.