Mid-Wales county named after the Forest of Radnor which forms its centre. Adjacent counties are: to the south Brecknockshire, to the west Cardiganshire, to the north Montgomeryshire, to the south-east Herefordshire and to the north-east Shropshire.

Principal towns include Llandrindod Wells, Rhyader and the village of Llanelwedd (a suburb of Builth Wells, Brecknockshire) where the annual Royal Welsh agricultural show is held.