Located 12 km north of the Welsh capital Caerdydd (Cardiff) in South Wales, it was the location of a 1st century Roman fort. Although it has a professional Quidditch team, its Wikipedia page does not list any wizarding sports or any other wizarding activity (Wikipedia).
Lexicon list of British and Irish Quidditch Teams
From the Web
Caerphilly Tourism: Visit Caerphilly
Castles of Wales: Caerphilly Castle