The Black Mountains is a group of hills on the England–Wales border. The larger Welsh part is located in south-east Powys and north-west Monmouthshire, and the smaller English part in western Herefordshire. The range lies approximately within a triangle defined by Abergavenny in the south-east, Hay-on-Wye in the north, and Llangors in the west; Talgarth and Crickhowell are also nearby.