The highest mountain in the group is Waun Fach whose heavily eroded peat summit plateau attains a height of . Its secondary summit Pen y Gadair Fawr at has a more distinctive peak shape. On the eastern ridge, the peak of Black Mountain stands on the Wales-England border, and is the highest point in England south of Great Whernside in Yorkshire. Other summits towards the northern end are Hay Bluff (Welsh: Penybegwn), , Rhos Dirion, and Lord Hereford's Knob or Twmpa, . Towards the south of the range are the more independent summits of Crug Mawr at , Pen Allt-mawr at and the peak of Pen Cerrig-calch which rises prominently above Crickhowell in the Usk Valley.