Hay-on-Wye in Hay is a sub-office of Hereford, and therefore although in Wales has an English postal address, being part of the HR3 postcode. Hay-on-Wye is a Welsh community with a Town Council. Its boundary follows the English border/Dulas Brook from the River Wye southeastwards for just over a kilometre, turns south-west to a point just south of Oakfield house, thence north to Greenpit Farm and north westwards, enclosing the Hay Showground and meeting the National Park boundary near the B4350, Brecon Road. From this point, it follows the National Park boundary to the River Wye and the river back to
Wye Valley well as in the adjoining Forest of Dean. The medieval boroughs of Goodrich and Chepstow, at each end of the Wye Gorge, may have originally been established at this time. Closely following the River Wye, Offa's Dyke was built in the 8th century under King Offa to mark out the boundary between England and Wales and is, today, the longest archaeological monument in Britain. Offa's Dyke Path long distance footpath today traces the route through the Wye valley on the English bank, while the Wye Valley Walk follows the Welsh bank. When the Normans conquered the region in the 11th