Herefordshire Worcestershire and Warwickshire" NUTS 2 region. The River Wye, which at is the fifth-longest in the United Kingdom, enters the county after briefly being its border with Powys. It flows through both Hereford and Ross-on-Wye before returning to Wales. Leominster is situated on the River Lugg, a tributary of the Wye. There are two Areas of Outstanding Natural Beauty in the county. The Wye Valley is located in the river's valleys south of Hereford, while the Malvern Hills are in the east of the county, along its border with Worcestershire. Herefordshire is one of the 39 historic counties of England.
River Monnow River Monnow The River Monnow () marks the England–Wales border for much of its length. After flowing through southwest Herefordshire, England, and eastern Monmouthshire, Wales, its confluence with the River Wye is approximately south of Monmouth. The Monnow rises near Craswall on Cefn Hill just below the high Black Mountains, Wales. It flows southwards, gaining the waters of its tributaries the Escley Brook and Olchon Brook near Clodock and the waters of the River Honddu, from the Welsh side of the Black Mountains, near Pandy. The river then flows briefly eastwards, to Pontrilas, where it is joined by its largest