Chepstow (Welsh: Cas-gwent) is a town and community in Monmouthshire, Wales, adjoining the border with Gloucestershire, England. It is located on the tidal River Wye, about 2 miles (3.2 km) above its confluence with the River Severn, and adjoining the western end of the Severn Bridge. Chepstow is located close to junction 2 of the M48 motorway, at the western end of the Severn Bridge. The bridge was opened in 1966 and has the second longest span of any bridge in the UK; it replaced the Aust-Beachley ferry. Before the Severn Bridge was opened, the old cast iron road bridge across the Wye at Chepstow, built in 1816 to replace earlier wooden structures, carried all the road traffic between South West England and South Wales and was the lowest bridging point of the Wye. The M48 motorway now connects Chepstow by road to Newport (18 miles (29 km)) and Cardiff (31 miles (50 km)) to the west, and Bristol (18 miles (29 km)) and London (124 miles (200 km)) to the east. To the north, the A466 up the Wye valley connects the town with Monmouth (16 miles (26 km)), and to the north-east the A48 links it with Gloucester (29 miles (47 km)).