Caerphilly is a town and community in Wales, United Kingdom. It is situated at the southern end of the Rhymney Valley. It is the largest town in Caerphilly County Borough, within the historic borders of Glamorgan, on the border with Monmouthshire. At the 2011 Census, the town had a population of 41,402 while the wider Caerphilly Local Authority area has a population of 178,806.
It is a commuter town for Cardiff and Newport, 7.5 miles and 12 miles away respectively, and is separated from the Cardiff suburbs of Lisvane and Rhiwbina by Caerphilly mountain. The town is perhaps best known outside of Wales for Caerphilly cheese.