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
Wales vessels lost and an average loss of life of about 78 sailors per year. Wartime action caused losses near Holyhead, Milford Haven and Swansea. Because of offshore rocks and unlit islands, Anglesey and Pembrokeshire are still notorious for shipwrecks, most notably the "Sea Empress" oil spill in 1996. The first border between Wales and England was zonal, apart from around the River Wye, which was the first accepted boundary. Offa's Dyke was supposed to form an early distinct line but this was thwarted by Gruffudd ap Llewellyn, who reclaimed swathes of land beyond the dyke. The Act of Union of