Cadair Berwyn or Cader Berwyn is a mountain summit in north-east Wales with a height of above sea level. It is the highest point in the Berwyn range, the highest in North East Wales and the highest significant summit in Wales outside the National Parks. Cadair Berwyn and Foel Cedig to the west are the two Marilyns that form the Berwyn range. The undulating plateau of the range also includes a large number of other summits above , including satellite summits of Cadair Berwyn and many which are classed as Nuttalls. The mountain lies on main ridge of the Berwyns which runs north–south. The eastern side of the ridge is characterised by steep drops and crags including Craig Berwyn north of the summit and Craig y Llyn to the south. Craig y Llyn forms the headwall of a cwm, and it is to this that the word cadair (chair in Welsh) presumably refers. Further north along the ridge is Cadair Bronwen, whilst to south the ridge continues to Moel Sych (, meaning 'dry hill'). It is often reported that Moel Sych, along the ridge, is of equal height, but Cadair Berwyn's spot height on the Ordnance Survey maps, where the trig point stands, is not the true summit. Cadair Berwyn's summit, south of the trig point, is taller than Moel Sych. This summit is listed as Cadair Berwyn New Top on the Nuttall list. However, the name given to it by its discoverer, Bernard Wright, was Craig Uchaf. In 1987 Bernard Wright, a rambler from Cheshire, was standing on Cadair Berwyn North Top (then said to be the highest mountain in Clwyd) when he noticed that a nearby peak appeared to be higher. After first denying it, the cartographers at the Ordnance Survey finally admitted that Bernard had discovered a 'new mountain' at 830 metres above sea level. Bernard's name for this peak was Craig Uchaf (highest rock) the topographical name fitting in well with those that the Welsh have been giving their landscape for centuries. Near the summit is a Bronze Age cairn. In 2014, accurate re-surveying using GPS by Myrddyn Phillips added an additional 2 metres to the height. Phillips uses the name Craig Berwyn rather than Cadair Berwyn for this summit. Several other summits in the area are listed as Hewitts or Nuttalls, including Foel Wen (, Welsh for white hill) and Mynydd Tarw (, bull mountain).