Pen-y-cae-mawr is a village in Monmouthshire, Wales.
It is situated within the NP15 postcode district, which is within the Usk post town.
NP15 is the only postcode district within the Usk post town.
The Usk post town is within the Newport postcode area.
Administrative Ward: Llangybi Fawr
Administrative District: Monmouthshire
Country: Wales
UK Parliament: Monmouth