Oldcastle () is a small village in Monmouthshire, south east Wales. Location Oldcastle is located six miles north of Abergavenny just off the A465 Abergavenny to Hereford road. History and amenities The village is on the River Monnow and very close to the Black Mountains and sits right next to the Wales-England border . The village is associated with John Oldcastle of an old Herefordshire landowning family through the medieval period. External links Oldcastle on Vision of Britain Oldcastle church The church entrance Villages in Monmouthshire