Foel Chwern is a Round cairn on the edge of the high plateau east of the Neath valley, and near the summit of Craig y Llyn. The headwaters of the River Rhondda are to the south-west. It is a burial monument dating to the Bronze Age, and is sited on the edge of a steep scarp slope, with a wide field of view to the north. The long distance footpath Coed Morgannwg Way runs close by the cairn. Conifer plantations of the Rheola Forest surround the site.