Cefn Hengoed is situated in the heart of Caerphilly, South Wales. It is bordered by Bargoed to the north, Ystradmynach to the south, Pontllanfraith to the east, and Nelson to the west. The river Rhymney flows through the village from its source just above Princetown and enters the sea at the Severn estuary in Cardiff Bay.
North of Cefn Hengoed is Bargoed Woodland Park, Caerphilly's newest country park. Walks can be taken along the Rhymney River and it's hard to believe that this quiet and natural place was once the site of the highest coal tip in Europe. Visitors can explore the fragments of old woodland that escaped the ravages of mining. The river, once trapped in a huge tunnel, is now alive with dippers, herons, kingfishers and otters.