A466 road about long and runs through the counties of Herefordshire and Gloucestershire in England, and Monmouthshire in Wales. It runs south from Kingsthorne, on the A49 south east of Hereford to Monmouth, crossing the A40. After crossing the River Wye at the Wye Bridge, Monmouth and Bigsweir Bridge near Llandogo, it follows a picturesque route south down the Wye valley through Tintern and Chepstow to the M48 motorway at junction 2. The road crosses the border between England and Wales at three places along its length: at Buckholt, Redbrook, and Bigsweir. It runs through an Area of Outstanding Natural Beauty, and
River Wye Gloucestershire, and Monmouthshire. The Wye abuts a range of other SSSIs in England and Wales, including the Upper Wye Gorge and Lower Wye Gorge. It is also a Special Area of Conservation and one of the most important rivers in the UK for nature conservation. It is an important migration route and wildlife corridor, as well as a key breeding area for many nationally and internationally important species. The river supports a range of species and habitats covered by European Directives and those listed under Schedule 5 of the Wildlife and Countryside Act 1981. In Powys the river lies within