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.
England–Wales border an exclave of Flintshire, between Bangor-on-Dee (in Wales) and Whitchurch (in England). Returning to the River Dee as far as Chirk, the boundary then loops to the west, following Offa's Dyke itself for about , and including within England the town of Oswestry, before reaching the River Vyrnwy at Llanymynech. It follows the Vyrnwy to its confluence with the River Severn, and then continues southwards, rising over Long Mountain east of Welshpool. East of Montgomery, the boundary again follows the line of Offa's Dyke for about , before looping eastwards to include within Wales a large area near Churchstoke. It