Wye Valley Wye Valley The Wye Valley Area of Outstanding Natural Beauty (AONB; ) is an internationally important protected landscape straddling the border between England and Wales. It is one of the most dramatic and scenic landscapes in Britain. The River Wye () is the fifth-longest river in the United Kingdom. The upper part passes through Rhayader, Builth Wells and Hay-on-Wye, but the area designated as an AONB covers surrounding a stretch lower down the river, from just south of Hereford to Chepstow. This area covers parts of the counties of Gloucestershire, Herefordshire and Monmouthshire, and is recognised in particular for its
England–Wales border 1972. Whether Monmouthshire was part of Wales, or an English county treated for most purposes as though it were Welsh, was also settled by the 1972 Act, which included it in Wales. The modern boundary between Wales and England runs from the salt marshes of the Dee estuary adjoining the Wirral Peninsula, across reclaimed land to the River Dee at Saltney just west of Chester. It then loops south to include within England an area southwest of Chester, before rejoining the Dee, and then loops east of the river to include within Wales a large area known as Maelor, formerly