The Rhymney Valley (Welsh: Cwm Rhymni) is a valley encompassing the villages of Abertysswg, Fochriw, Pontlottyn, Tirphil, New Tredegar, Aberbargoed, Rhymney, and Ystrad Mynach, and the towns of Bargoed and Caerphilly, in south-east Wales, formerly famous for its coal mining and iron industries.