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
England–Wales border of Wessex in about 885. Alfred's son Edward the Elder also secured homage from the Welsh, although sporadic border unrest continued. In the early 10th century, a document known as "The Ordinance Concerning the Dunsaete" records procedures for dealing with disputes between the English and the Welsh, and implies that areas west of the Wye in Archenfield were still culturally Welsh. It stated that the English should only cross into the Welsh side, and vice versa, in the presence of an appointed man who had the responsibility of making sure that the foreigner was safely escorted back to the crossing