The Rhymney Valley (Welsh: Cwm Rhymni) is one of the South Wales valleys, with the Rhymney River forming the border between the historic counties of Glamorgan and Monmouthshire. Between 1974 and 1996 a Rhymney Valley local government district also existed (one of six of Mid Glamorgan).[1] The valley encompasses the villages of Abertysswg, Fochriw, Hengoed, Pontlottyn, Tir-Phil, New Tredegar, Nelson, Rhymney, and Llanbradach, and the towns of Bargoed, Caerphilly, Ystrad Mynach and Aberbargoed.