This from Grough:
For decades, Tryfan has qualified as a Welsh 3,000-footer, a boast that, recently, has been in doubt. But now, the shapely mountain in the Ogwen Valley is swelling with a little more pride. It stands officially at 917.5m, easily beating the mark at a comfortable 3,010ft. A trio of amateur surveyors, John Barnard, Graham Jackson and Myrddyn Phillips using very unamateurish GPS measuring equipment finally nailed the mountain’s true height. We can now expect future OS maps to be amended. The peak has commanded respect among mountain lovers mainly because it looks exactly like a mountain should, but also because it qualified as one of the 15 or so 3,000-footers in Snowdonia. But, with an Ordnance Survey determined height of 915m – just 60cm above the metric equivalent of the magic 3,000ft, it was always on the hit list of the enthusiastic trio, who have already been responsible for the demotion from the munro tables of Sgurr nan Ceannaichean. The three men took their surveying equipment to the summit and strapped it to the rocks for long enough to determine its true height. And this afternoon, Ordnance Survey, which has been working with the sleuths, announced the result.
Not that it will make any difference to the aficionados of mountains who climb our peaks for their intrinsic worth rather than an arbitrary figure printed on the map next to its summit. It’s just that they can now have the satisfaction that they’re standing eight feet taller.