The only upland area in Pembrokeshire Coast National Park, these hills rise to a height of 536m at Foel Cwmcerwyn. They encompass a fascinating prehistoric landscape, scattered with hill forts, standing stones and burial chambers, and are famous as the source of the mysterious bluestones of Stonehenge. The ancient Golden Road track, once part of a 5000-year-old trade route between Wessex and Ireland, runs along the crest of the hills, passing prehistoric cairns and the stone circle of Bedd Arthur.