Moel y Cerrig Duon tops the eastern end of a long peat bog plateau along with Llechwedd Du. Its summit has a conical shape, rising suddenly from the bog. The summit itself is grassy, marked by a small cairn and a stake. To the north-east is Foel y Geifr, to the east Cyrniau Nod and to the west is Llechwedd Du, Esgeiriau Gwynion, and Aran Fawddwy.