The Carneddau are the largest continuous stretch of mountain land over 2,500 feet in the country. They are not as rugged as the Snowdon massif or the Glyderau but are impressive nevertheless. Much of the higher tops is covered with rough grass and heather, with patches of shattered rocks. Pen-yr-Ole-Wen lies on the western edge of the range and dominates the Nant Ffrancon pass. Continuing along the ridge from here Carnedd Dafydd is reached, then Carnedd Llewellyn and on to various lower summits. To the north and west of the ridge are mostly grassy slopes, while to the east there are some high cliffs, deep valleys and small lakes. The Carneddau range is home to the only population of wild horses in the United Kingdom.