Hay-on-Wye the north-easternmost tip of the Brecon Beacons National Park, just north of the Black Mountains. The town is just on the Welsh side of the border with Herefordshire, England, here defined by the Dulas Brook. Where the brook joins the River Wye just north of the town, the border continues northwards along the river. The Wye was the boundary between the former counties and districts of Radnorshire and Brecknockshire. The adjacent village of Cusop lies on the English side of the Dulas Brook. The nearest city is Hereford, county town of Herefordshire, some to the east. The Royal Mail depot
Wye Valley Walk Hafren, having passed within viewing distance of the source of the River Wye on Plynlimon near Aberystwyth, a total of . The Wye Valley Walk is marked out by circular yellow waymark arrows, finger posts, and signs showing the path's logo, a leaping salmon. Most of the route follows Public Rights of Way. Some parts are permissive paths where owners have agreed for them to be used. Parts of Plynlimon are open countryside in which there is a right to roam established by the Countryside and Rights of Way Act 2000. The route passes through Chepstow, the Wye Valley AONB,